The document summarizes the total synthesis of (±)-spiroindimicins B and C, which are alkaloids isolated from a deep-sea marine actinomycete. Key steps in the synthesis include installing a spirocenter using an intramolecular Heck reaction, forming a pentacyclic spirobisindole through Fischer indolization, and constructing a trisubstituted pyrrole ring via a late-stage Schöllkopf–Magnus–Barton–Zard reaction. The synthesis confirms the unique heteroaromatic structure of these natural products and demonstrates the use of mild reactions to install functional groups like the spirocenter and pyrrole ring.
Determination of nonlinear absorption (β) and refraction (n2)by the Z-scan me...IOSR Journals
Potassium Pentaborate nonlinear optical (NLO) material was synthesized by the solution growth method. The grown crystals were subjected to structural, optical and mechanical property studies. Crystal with excellent transparency were grown with maximum size of 9mm×8mm×5mm and the grown crystals were characterized by single crystal Single crystal XRD, FT-IR, TGA-DTA&DSC, and UV–vis-NIR studies. The crystal belongs to orthorhombic with a space group of mm2 having unit-cell dimensions a = 11.068Åb= 11.175Å c = 9.058Åand α = 90°; β = 90°; and γ =90°; Z=4, at 298(2) K. The second-order nonlinear optical property of the polycrystalline sample has been confirmed by Kurtz-Perry powder SHG analysis. Third order nonlinear optical properties were also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also calculated.
Determination of nonlinear absorption (β) and refraction (n2)by the Z-scan me...IOSR Journals
Potassium Pentaborate nonlinear optical (NLO) material was synthesized by the solution growth method. The grown crystals were subjected to structural, optical and mechanical property studies. Crystal with excellent transparency were grown with maximum size of 9mm×8mm×5mm and the grown crystals were characterized by single crystal Single crystal XRD, FT-IR, TGA-DTA&DSC, and UV–vis-NIR studies. The crystal belongs to orthorhombic with a space group of mm2 having unit-cell dimensions a = 11.068Åb= 11.175Å c = 9.058Åand α = 90°; β = 90°; and γ =90°; Z=4, at 298(2) K. The second-order nonlinear optical property of the polycrystalline sample has been confirmed by Kurtz-Perry powder SHG analysis. Third order nonlinear optical properties were also studied by Z-scan techniques. Nonlinear absorption and nonlinear refractive index were found out and the third order bulk susceptibility of compound was also calculated.
Investigation on the Growth and Physio-Chemical Properties of L-Alanine Mixed...IJERA Editor
Pure and L-alanine an aminoacid mixed bisthiourea cadmium bromide chloride single crystals were grown by slow evaporation technique. A drastic change in morphology was inferred with the concentration of L-alanine. Mixed crystals have better optical transparency as well as NLO efficiency than the pure BTCBC which were imperative for nonlinear applications. Also L-alanine mixing increases the hardness. The AC conductivity of the grown crystals increases with increasing concentration of L-alanine.
Synthesis of 1,5 Benzodiazepines A ReviewYogeshIJTSRD
Benzodiazepines are bicyclic heterocycles having medicinal importance. As a result several greener procedures have been developed using mild conditions and recyclable catalysts, easy work up good yields, multi component reactions less wastage and solvent less synthesis. Deepali Mahajan | Abhishek Raina "Synthesis of 1,5- Benzodiazepines: A Review" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43842.pdf Paper URL: https://www.ijtsrd.com/chemistry/other/43842/synthesis-of-15-benzodiazepines-a-review/deepali-mahajan
Synthesis and Characterization of Elastin-Like PolypeptidesJustin Coleman
Elastin-Like Polypeptides (ELP) are class of biopolymers that are composed of a repeating pentapeptide sequence that mimics mammalian elastin with the structure VPGXG. ELP has a Low Critical Solution Temperature (LCST) which enables it to dissolve in solution at lower temperatures and above the LCST the ELP aggregates into insoluble coacervates. This work makes use of a robust chemistry to attach various biocompatible Lewis bases to the ELP molecules. This will allow the ELP to act as an electron donor to specific types of atoms that are electron deficient. These atoms will act as coordination centers for the ELP molecules and allow them to exhibit certain advantageous and tailorable properties. This work will explore how stereochemistry, and different electron deficient molecules change the behavior of ELP and its transition temperature. Nanodrop UV vis will be used to explore how changing the electron deficient molecules effects the electrons in the ELP and thus the UV wavelength absorbance. FT-IR will demonstrate the change in functional groups after the reactions have occurred. Lastly, dynamic light scattering will be used to show a change in transition temperature of the ELP when exposed to different variables.
One Pot Hydrothermal Synthesis Characterizations Of Silver Nanoparticles On R...IOSRJAC
Graphene-based nanocomposite have significant applicability in catalysis, electronics, medicine, and energy. In this report silver nanoparticles (AgNPs) with Reduced Graphene Oxide (RGO) - nanocomposite was prepared by a one-pot hydrothermal process using silver nitrate as a precursor. Under hydrothermal process Graphene oxide (GO) was reduced to reduced graphene oxide (RGO), without using chemical reagents. As synthesized (Ag-RGO) nanocomposite was characterized by XRD, UV Vis-spectroscopy, Scanning electron microscope, and Raman spectroscopy. Antimicrobial activities of the composite were investigated against both Gram-positive and Gram-negative bacteria. The results demonstrate that Ag-RGO nanocomposite was a strong bactericide against Gram-negative bacteria. Antioxidant activity was evaluated for bare GO, Ag and Ag-RGO nanocomposite by DPPH radical scavenging assay. It was observed that Ag/RGO nanocomposite has enhanced antioxidant activity than bare GO and Ag.
Synthesis, spectroscopic, magnetic properties and superoxide dismutase (SOD) ...IOSR Journals
Three new ternary copper(II) complexes formulated as [Cu(HIda)(bipy)] 1; [Cu(HIda)(phen)] 2; [Cu(HIda)(dmp)] 3; where HIda =N-(2-hydroxyethyl)-2- iminodiacetic acid ; bipy = 2, 2’- bipyridine; phen = 1,10- phenanthroline; dmp = 2,9-dimethyl 1,10-phenanthroline, have been synthesized and characterized by partial elemental analysis, FAB-mass (m/z), EPR, UV-visible and CV measurements. The magnetic and spectroscopic data of all these complexes 1-3 indicate distorted octahedral geometry. The EPR spectra of these complexes in frozen DMSO solutions showed a single at g ca. 2. The trend in g-value (g||>g>2.0023) suggests that the unpaired electron on copper (II) has dx2–y2 character. The SOD activities of the complexes have been investigated. Antibacterial and antifungal activity of these complexes were also measured and discussed.
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Effluents containing heavy metals can be
remediated with the help of dead microorganisms by the process
known as biosorption. In this study the dead biomass 1of fungus
Aspergillus flavus was used for the biosorption of heavy metals
i.e., Zinc and Nickel. The capacity of biosorption by the dead
biomass of Aspergillus flavus was evaluated at room temperature
with different parameters which are; pH, contact time, biomass
concentration and metal ion concentration. The biosorption
capacity for Zn was found to be 47.36% at room temperature, at
pH 6.5, with biomass concentration of 2g/L having contact time of
50 min and solution concentration of 2ppm. Biosorption capacity
for Ni was found to be 61.60% at room temperature, at pH 5,
with biomass concentration of 2g/L having contact time of 60 min
and solution concentration of 2ppm. . In this study, desorption of
the heavy metals by 0.1M HCl was found to be effective. Fungal
biomass was recovered for reuse.
Investigation on the Growth and Physio-Chemical Properties of L-Alanine Mixed...IJERA Editor
Pure and L-alanine an aminoacid mixed bisthiourea cadmium bromide chloride single crystals were grown by slow evaporation technique. A drastic change in morphology was inferred with the concentration of L-alanine. Mixed crystals have better optical transparency as well as NLO efficiency than the pure BTCBC which were imperative for nonlinear applications. Also L-alanine mixing increases the hardness. The AC conductivity of the grown crystals increases with increasing concentration of L-alanine.
Synthesis of 1,5 Benzodiazepines A ReviewYogeshIJTSRD
Benzodiazepines are bicyclic heterocycles having medicinal importance. As a result several greener procedures have been developed using mild conditions and recyclable catalysts, easy work up good yields, multi component reactions less wastage and solvent less synthesis. Deepali Mahajan | Abhishek Raina "Synthesis of 1,5- Benzodiazepines: A Review" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-5 | Issue-5 , August 2021, URL: https://www.ijtsrd.com/papers/ijtsrd43842.pdf Paper URL: https://www.ijtsrd.com/chemistry/other/43842/synthesis-of-15-benzodiazepines-a-review/deepali-mahajan
Synthesis and Characterization of Elastin-Like PolypeptidesJustin Coleman
Elastin-Like Polypeptides (ELP) are class of biopolymers that are composed of a repeating pentapeptide sequence that mimics mammalian elastin with the structure VPGXG. ELP has a Low Critical Solution Temperature (LCST) which enables it to dissolve in solution at lower temperatures and above the LCST the ELP aggregates into insoluble coacervates. This work makes use of a robust chemistry to attach various biocompatible Lewis bases to the ELP molecules. This will allow the ELP to act as an electron donor to specific types of atoms that are electron deficient. These atoms will act as coordination centers for the ELP molecules and allow them to exhibit certain advantageous and tailorable properties. This work will explore how stereochemistry, and different electron deficient molecules change the behavior of ELP and its transition temperature. Nanodrop UV vis will be used to explore how changing the electron deficient molecules effects the electrons in the ELP and thus the UV wavelength absorbance. FT-IR will demonstrate the change in functional groups after the reactions have occurred. Lastly, dynamic light scattering will be used to show a change in transition temperature of the ELP when exposed to different variables.
One Pot Hydrothermal Synthesis Characterizations Of Silver Nanoparticles On R...IOSRJAC
Graphene-based nanocomposite have significant applicability in catalysis, electronics, medicine, and energy. In this report silver nanoparticles (AgNPs) with Reduced Graphene Oxide (RGO) - nanocomposite was prepared by a one-pot hydrothermal process using silver nitrate as a precursor. Under hydrothermal process Graphene oxide (GO) was reduced to reduced graphene oxide (RGO), without using chemical reagents. As synthesized (Ag-RGO) nanocomposite was characterized by XRD, UV Vis-spectroscopy, Scanning electron microscope, and Raman spectroscopy. Antimicrobial activities of the composite were investigated against both Gram-positive and Gram-negative bacteria. The results demonstrate that Ag-RGO nanocomposite was a strong bactericide against Gram-negative bacteria. Antioxidant activity was evaluated for bare GO, Ag and Ag-RGO nanocomposite by DPPH radical scavenging assay. It was observed that Ag/RGO nanocomposite has enhanced antioxidant activity than bare GO and Ag.
Synthesis, spectroscopic, magnetic properties and superoxide dismutase (SOD) ...IOSR Journals
Three new ternary copper(II) complexes formulated as [Cu(HIda)(bipy)] 1; [Cu(HIda)(phen)] 2; [Cu(HIda)(dmp)] 3; where HIda =N-(2-hydroxyethyl)-2- iminodiacetic acid ; bipy = 2, 2’- bipyridine; phen = 1,10- phenanthroline; dmp = 2,9-dimethyl 1,10-phenanthroline, have been synthesized and characterized by partial elemental analysis, FAB-mass (m/z), EPR, UV-visible and CV measurements. The magnetic and spectroscopic data of all these complexes 1-3 indicate distorted octahedral geometry. The EPR spectra of these complexes in frozen DMSO solutions showed a single at g ca. 2. The trend in g-value (g||>g>2.0023) suggests that the unpaired electron on copper (II) has dx2–y2 character. The SOD activities of the complexes have been investigated. Antibacterial and antifungal activity of these complexes were also measured and discussed.
International Journal of Pharmaceutical Science Invention (IJPSI)inventionjournals
is an international journal intended for professionals and researchers in all fields of Pahrmaceutical Science. IJPSI publishes research articles and reviews within the whole field Pharmacy and Pharmaceutical Science, new teaching methods, assessment, validation and the impact of new technologies and it will continue to provide information on the latest trends and developments in this ever-expanding subject. The publications of papers are selected through double peer reviewed to ensure originality, relevance, and readability. The articles published in our journal can be accessed online
Research Inventy : International Journal of Engineering and Science is published by the group of young academic and industrial researchers with 12 Issues per year. It is an online as well as print version open access journal that provides rapid publication (monthly) of articles in all areas of the subject such as: civil, mechanical, chemical, electronic and computer engineering as well as production and information technology. The Journal welcomes the submission of manuscripts that meet the general criteria of significance and scientific excellence. Papers will be published by rapid process within 20 days after acceptance and peer review process takes only 7 days. All articles published in Research Inventy will be peer-reviewed.
Effluents containing heavy metals can be
remediated with the help of dead microorganisms by the process
known as biosorption. In this study the dead biomass 1of fungus
Aspergillus flavus was used for the biosorption of heavy metals
i.e., Zinc and Nickel. The capacity of biosorption by the dead
biomass of Aspergillus flavus was evaluated at room temperature
with different parameters which are; pH, contact time, biomass
concentration and metal ion concentration. The biosorption
capacity for Zn was found to be 47.36% at room temperature, at
pH 6.5, with biomass concentration of 2g/L having contact time of
50 min and solution concentration of 2ppm. Biosorption capacity
for Ni was found to be 61.60% at room temperature, at pH 5,
with biomass concentration of 2g/L having contact time of 60 min
and solution concentration of 2ppm. . In this study, desorption of
the heavy metals by 0.1M HCl was found to be effective. Fungal
biomass was recovered for reuse.
ACETYLATION OF BENZYLIC ALCOHOLS OVER BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (B...EDITOR IJCRCPS
BiFeO3 (BFO), Bi0.86Sm0.07Eu0.07FeO3 (BSEFO), and Bi0.86Sm0.07Cd0.07FeO3 (BSCFO) nanopowders were prepared by the sol-gel
combustion method and the catalytic performances were evaluated in acetylation reaction of benzyl alcohol. The physical chemical
properties of catalysts were characterized by using XRD, FT-IR, scanning electron microscope (SEM), EDX and BET surface.
Efficient acetylation of benzyl alcohol was carried out over all the nano powders using acetyl chloride/ acetonitrile at room
temperature. Among the nanopowders, BSCFO showed the highest catalytic performance and the yield of benzyl acetate was 89,
45, and 69 percent over BSCFO, BFO, and BSEFO, respectively. Partial substitution of Sm-Eu and Sm-Cd in bismuth ferrite
improved the catalytic performance and increased the specific surface area of the catalysts. A direct relationship was resulted
between catalytic performance and surface of catalysts, where BSCFO with the highest surface area (111m2/g) exhibited the
superior catalytic performance. The quantitative yield for acetate product was also resulted for acetylation of p-methyl benzyl
alcohol, p-nitro benzyl alcohol and p-chloro benzyl alcohol on BSCFO. The catalysts showed good reusability in the process. The
study confirmed the catalysts could be promising catalyst for acetylation of alcohols.
Keywords: Europium, Samarium, Bismuth ferrites, nano perovskite, doping, Acetylation, benzylic alcohols.
Sonocatalytic Performance of Fe3O4 Cluster Microspheres Gratiphic Carbon Comp...ijtsrd
Fe3O4 g C3N4 composite was synthesized using hydrothermal simple and facile techniques. The sonocatalytic activity of the magnetic Fe3O4 g C3N4 composite was studied through the H2O2 assisted system for degradation of water soluble organic pollutants such as methylene blue MB , rhodamine B RhB and methyl orange MO . X ray diffraction XRD and scanning electron microscopy SEM equipped were employed for the characterizing the structure and morphology of the so synthesized nanohybrid. The integration of H2O2 and catalyst dosage enhaced the sonocatalytic degradation of dyes. Furthermore, the magnetic property of the sample leaded to easier separation of the microhybrid, made it recyclable with a negligible decline in the dye degradation even after four consecutive recycles. Xuan Sang Nguyen "Sonocatalytic Performance of Fe3O4 Cluster Microspheres/Gratiphic Carbon Composite for Efficient Degradation of Organic Dyes" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-7 | Issue-3 , June 2023, URL: https://www.ijtsrd.com.com/papers/ijtsrd57418.pdf Paper URL: https://www.ijtsrd.com.com/chemistry/environmental-chemistry/57418/sonocatalytic-performance-of-fe3o4-cluster-microspheresgratiphic-carbon-composite-for-efficient-degradation-of-organic-dyes/xuan-sang-nguyen
With the increasing researches in the field of nanotechnology, various nanoparticles have become a source of interest among the nano technologists because of their great properties, like the optical properties of Cadmium Sulfide Nanoparticles are amazing and also easy to synthesize, but to make sure its quality it is equally essential to make out characterize it, this file will do the same in a lucid way!!
Structural, morphological, and photoluminescence study of Europium doped spin...AI Publications
Nanocrystalline Eu-doped Zinc aluminate spinel was produced by a combustion method. Different methods, including X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), and photoluminescence spectroscopy, were used to examine the prepared spinel type ZnAl2O4 ceramic material and characterize its structural, morphological, and photoluminescent properties. The formation of a pure phase with a spinel structure and the space groupfd3 ̅m is confirmed by the zinc aluminate material's X-ray diffraction pattern. Scan and transmission electron microscopy were used to further establish the average surface structure and crystalline size. The PL spectra show the strongest emission at 616 nm corresponds to the 5D0 → 7F2 transition of Eu3+. Photometric parameters like CIE coordinates and CCT values show that prepared phosphor that gives off a bright red light is used in the display and lamp industries.
Effect of mixed species biofilm on corrosion of cast iron
seminar presentation
1. Total syntheses of (±)-spiroindimicins B and C
enabled by a late-stage Schöllkopf–Magnus–
Barton–Zard (SMBZ) reaction
Presenter: 鄭裕豐
Student ID: 401260018
Date: 5/26/2016
Lachlan M. Blair and Jonathan Sperry*
Chem. Commun., 2016, 52, 800
DOI: 10.1039/c5cc09060a
3. Author
Jonathan Sperry
Biography:
• Feb 2014- 2019. RSNZ Rutherford Discovery Fellow
• Feb 2012- present. Senior Lecturer in Organic and Medicinal Chemistry, University of
Auckland, New Zealand
• Nov 2009- Feb 2012. Lecturer in Organic and Medicinal Chemistry, University of
Auckland, New Zealand
• Nov 2007- Nov 2009. Postdoctoral Research Fellow, University of Auckland, New Zealand,
(RSNZ Marsden Fund, Prof. M. A. Brimble)
• Mar 2006- Nov 2007. Honorary Postdoctoral Research Fellow, University of Auckland,
New Zealand, (Prof. M. A. Brimble)
• Oct 2002- Feb 2006. Ph.D Synthetic Organic Chemistry, University of Exeter, UK.
Biomimetic Oxidations in Natural Product Synthesis (Prof. C. J. Moody)
• 1999-2002. BSc (Hons) Biological and Medicinal Chemistry, 1st class. University of Exeter,
UK. Final year project: A Diels Alder approach to Vitamin B6 analogues
3
4. Research Interest
• Organic Synthesis
• Medicinal chemistry
• Sustainable Synthesis / Green Chemistry
Lachlan M. Blair
• Postgraduate student of Jonathan Sperry
4
5. Abstract
• The spiroindimicins are a family of structurally unprecedented
alkaloids isolated from the deep-sea-derived marine actinomycete
Streptomyces sp. SCSIO 03032.
• The total syntheses of (±)-spiroindimicins B and C are disclosed, the
first of any member of this family.
• Central to the successful strategy was installing the spirocentre using
a mild intramolecular Heck reaction, the assembly of a pentacyclic
spirobisindole by Fischer indolization and a late-stage Schöllkopf–
Magnus–Barton–Zard (SMBZ) reaction to construct the trisubstituted
pyrrole.
5
6. Introduction
• Deep-sea organisms have evolved to survive under their extreme
environment by adapting a wide range of their biochemical processes
and metabolic pathways
• The spiroindimicins are a family of structurally unprecedented
alkaloids isolated from the deep-sea-derived marine actinomycete
Streptomyces sp. SCSIO 03032.
6
7. • Streptomyces sp. SCSIO 03032 produces a range of structurally
unprecedented natural products including spiroindimicins A–D (1–4)
• Biological evaluation revealed 2–4 are moderately cytotoxic to various
cancer cell lines
Introduction
7
8. Introduction
Schöllkopf–Magnus–Barton–Zard (SMBZ) reaction
• The Barton-Zard reaction is a route to pyrrole derivatives via the
reaction of a nitroalkene with an α-isocyanoacetate under basic
conditions. It is named after Derek Barton and Samir Zard who first
reported it in 1985.
• Considering Magnus reported this reaction the year prior to Barton
and Zard, the synthesis should be termed the Schöllkopf–Magnus–
Barton–Zard (SMBZ) reaction (names in chronological order according
to publication date)
8
11. Synthesis (10 → 9)
• SN2 reaction
• SN2’ reaction
• Occurs as double bond presents
• SN2 reaction and SN2’ reaction will compete to each other and
produce different product respectively
11
15. Synthesis (9 → 8 and 9 → 12)
• Mechanism of reaction expected by author (9→8)
15
16. Synthesis (9 → 8 and 9 → 12)
• Mechanism of reaction in fact (9→12)
16
17. Synthesis (9 → 8 and 9 → 12)
• Mechanism of reaction(9→12)
• Reinsertion of hydridopalladium species: PdH can also be scavenged by
starting alkene, which is always more reactive than the Heck product due to
its smaller size. This process is well-known as it leads to the isomerization of
alkenes, which results in the formation of isomeric Heck products
• Interestingly, silver nitrate could be added to the reductive conditions to
increase the yield of (±)-12 (63% vs. 93%).
17
18. Synthesis (9 → 8 and 9 → 12)
• Nuclear Overhauser effect (NOE)
• The transfer of nuclear spin polarization from one spin bath to another spin
bath via cross-relaxation. It is a common phenomenon observed by NMR
spectroscopy
• NOE occurs through space, not through chemical bonds. Thus, atoms that are
in close proximity to each other can give a NOE
• The inter-atomic distances derived from the observed NOE can often help to
confirm a precise molecular conformation
• Some examples of two-dimensional NMR experimental techniques exploiting
the NOE include nuclear Overhauser effect spectroscopy (NOESY),
heteronuclear Overhauser effect spectroscopy (HOESY) and many more.
18
21. Synthesis (8→7)
• Fischer indolization reaction
• A chemical reaction that produces the aromatic heterocycle indole from a
(substituted)phenylhydrazine and an aldehyde or ketone under acidic conditions
• The reaction was discovered in 1883 by Hermann Emil Fischer.
21
26. Synthesis (7→15)
• Compound 15 (compound 6 with Boc attach to N atom on indole) will
be formed by 3-step reaction via formation of compound 13 and 14.
26
30. Synthesis (15→17)
• reaction according to study by T. Mukaiyama and K. Saigo (Chem.
Lett., 1973, 479.)by adding 1 eq. TiCl4 + 2 eq. Et3N + 1.1 eq. thiol.
• In the end the compound 15 remains unreacted
30
32. Synthesis (17→16+18)
• this reaction will produce 2 compounds, compound 16 and compound 18
(ratio= 1.3:1)
32
33. Synthesis (17→16+18)
• To form compound 16 as much as possible from 18, add 1.1eq. TiCl4, 1.5 eq.
K2CO3 and CH2Cl2 as solvent and react for 2 hours in room temperature.33
34. Synthesis (16→19)
Mechanism of Schöllkopf–Magnus–Barton–Zard (SMBZ) reaction
• compound 18 itself is viable substrate for SMBZ reaction ( but lower yield (31%) than
conversion from compound 16 (62%))
(structure confirmed by X-ray analysis)
34
38. Conclusion
• In summary, the first total syntheses of spiroindimicins B and C have
been achieved, which serve to confirm the unique heteroaromatic
structure of these deep-sea-derived natural products.
• Some observations with implications beyond this synthetic study
include:
• (1) construction of all-carbon spirocentre using an intramolecular Heck
reaction under mild, reductive conditions promoted by silver(I);
• (2) successful application of the Fischer indolization to construct a pentacyclic
spirobisindole;
• (3) a late-stage SMBZ reaction using both a vinyl sulfoxide and a vinyl sulfone
to form a trisubstituted pyrrole.
38
39. References
• E. M. Boyd and J. Sperry, Org. Lett., 2015, 17, 1344
• D. H. R. Barton and S. Z. Zard, J. Chem. Soc.,Chem. Commun., 1985, 1098
• T. Mukaiyama and K. Saigo, Chem. Lett., 1973, 479.
• Y. Oikawa, T. Yoshioka, K. Mohri and O. Yonemitsu, Heterocycles, 1979, 12,
1457
• A. Nakhi, B. Prasad, U. Reddy, R. M. Rao, S. Sandra, R. Kapavarapu, D.
Rambabu, G. R. Krishna, C. M. Reddy, K. Ravada, P. Misra, J. Iqbal and M.
Pal, Med. Chem. Commun., 2011, 2, 1006
• N. H. Cromwell and H.-K. Leung, J. Org. Chem., 1976, 41, 3241
• M. M. Abelman and L. E. Overman, J. Org. Chem., 1987, 52, 4130
• R. Peng and M. S. VanNieuwenhze, Org. Lett., 2012, 14, 1962
• G. Stork and J. E. Dolfini, J. Am. Chem. Soc., 1963, 85, 2872
39