The Cannizzaro reaction is a chemical reaction discovered by Italian chemist Stanislao Cannizzaro in 1853. It involves the disproportionation of an aldehyde in the presence of a strong base. One aldehyde molecule is oxidized to the corresponding carboxylic acid, while another is reduced to the alcohol. The reaction allows the conversion of aldehydes lacking an alpha hydrogen to the corresponding acid and alcohol. It has various applications in organic synthesis and is an important reaction in chemistry.

6. Synthesis

13. Mechanism

14. In case Dianion form

15. In Aromatic aldehyde

17. In case of aldehydes that do have α-hydrogens, the aldol condensation reaction takes place preferentially.

19. The Biological Analogue of the Cannizzaro Reaction

28. 4 ) When a mixture of Formaldehyde and a non Enolizable aldehyde is treated with a strong base, the later is preferentially reduced to alcohol while formaldehyde is oxidized to formic acid. This variant is known as crossed Cannizzaro reaction . ILLUSTRATIONS

34. Intramolecular Cannizaro Reaction

35. Mechanism Step 1 Step 2 Step 3

48. Tishchenko reaction A variant of the Cannizzaro reaction, known as the Tischenko reaction is a disproportionate reaction of an Aldehyde lacking a hydrogen atom in the alpha position in the presence of an Alcoxide. Catalyst are aluminium alkoxides or sodium alkoxides . In this reaction the alcohol and acid products combine to form an ester .

49. Tishchenko reaction Para Benzaldehyde

51. Mechanism

55. Recent Literature

56. A convenient disproportionation or reduction of aldehydes is promoted by lithium bromide and triethylamine in a solvent-free environment at room temperature. Recent Literature

57. Recent Literature

59. Meerwein-Ponndorf-Verley reaction

62. One-Pot Oxidation-Cannizzaro Reaction of Aryl Methyl Ketones

64. One-Pot Oxidation-Cannizzaro Reaction of Aryl Methyl Ketones

70. Cannnizzaro Reaction by Marvi jabbar

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