Gilman reagent, also known as organocopper reagents, are prepared by reacting organomagnesium, organolithium, or organozinc reagents with copper(I) salts. Gilman reagents react with a variety of electrophiles including acid chlorides, aldehydes, ketones, epoxides, and alkyl halides. Some common reactions of Gilman reagents are: 1) reactions with acid chlorides to form ketones, 2) coupling reactions between two different alkyl halides to form C-C bonds, and 3) conjugate addition reactions of the organocopper reagent to unsaturated carbonyl compounds like enones. Gilman reagents offer advantages over Grignard reagents for

1. GILMAN REAGENT
Presented to :- Dr. Dharminder Sharma
Presented By :- Manish Kumar
Roll No. 4857
M.Sc. Chemistry(4th sem)
Practical code :- CH-526
Date :- 17 June, 2021

2. Introduction:
• Gilman reagent also known as organocopper reagents.
• Organocopper reagents are prepared by transmetallating the
organomagnesium, organolithium or organozinc reagent with copper(I) salts.
• reactivity of organocuprates with electrophiles follows the order:
RCOCl > R-CHO > R-OTs > R-I > R-Br > R-Cl > RCOR > R-CO2R' R-CN > RCH=CH2
R = alkyl, aryl or heteroaryl and can have remote functionaliyt such as
ethers, aetal or ketals

3. The Common Reaction Of Gilman Reagent:
1) Reactions with Acid Chlorides 2) Coupling Reactions
3) Conjugate Addition 4) Reactions with Aldehydes and Ketones
5) Reactions with Epoxides
 Reactions With Acid Chloride: The reaction of a dialkylcuprate and acid chloride
is a preferred method to synthesize ketones. Unlike in the case of Grignard
reagents, the ketones formed do not react with organocopper reagent.

4.  Coupling Reactions:- Organocuprates can replace halide ion from primary and
secondary alkyl halides to give cross-coupled products. This method provides
effective route for the construction C-C bond between two different alkyl halides,
which is not possible by the well known Wurtz coupling reaction, in which a
number of products are formed.
 Similar results are obtained from the reactions of aryl halides and organocuprates

5. Conjucate Addition Reaction: The organocopper reagents are softer than Grignard
reagents (because copper is less electropositive than magnesium), and add in conjugate
fashion to the softer C=C double bond.
• The mechanism of the transfer of the alkyl group from the organocuprates to the β-position
of the carbonyl compounds is uncertain. It is believed that initially a d- π* complex between
the organocopper(I) species and the enone is formed followed by the formation of a Cu(III)
intermediate which may undergo reductive elimination to form the product.

6.  In the case of enones, consecutive addition of the organocopper reagent and alkyl halides,
two different alkyl groups can be introduced in one operation.

7. Reactions With Aldehyde And Ketone: Organocuprates react with aldehydes to give
alcohols in high yield (Scheme 8). In the presence of chlorotrimethylsilane, the corresponding
siliylenol ethers can be obtained.

8. Reactions With Epoxide: The epoxide is attacked by organocopper reagents at the least
substituted carbon atom giving the corresponding alcohol.
 In disubstituted epoxide inversion of configuration occurs in the ring carbon because reaction
is SN2 reaction.
O H
H
O
H
H
H
Ph Ph Ph
Ph
CH3
CuLi
H2
O/H+

9. High Order Cuprates: Cuprates are useful but there are a few problems associated with
them. To overcome these limitations, Lipshutz developed higher order mixed cuprates,
R2Cu(CN)Li2, by the reaction of organolithium reagent with cuprous cyanide.
2R-Li + CuCN R2Cu(CN)Li2
 Higher order cuprates show greater reactivity compared Gilman reagents with alkyl halides,
even secondary halides. For example, (S)-2-bromooctane reacts with EtMeCu(CN)Li at 0 oC to
give (R)-3-methylnonane in 72% yield

10. Thank you