what is the mechanism of a cannizaro reaction

1. the attack of oh- as a nucleophile on the 1st molecule

2. h- transfer from 1st to 2nd molecule

3. h(plus) from carboxylic acid to alkoxide

as shown above the cannizzaro reaction begins with the attack of hydroxide ion on th C=O group. the second step is the rate determining step of the reaction as it is difficult to break C-H bond and tranfer hydride to carbonyl carbon of other group and making it alcohol by gaining H+ from solvent or from COOH portion as shown in the second figure of the first reaction. so it is a redox reaction of an aldehyde lacking hydrogen at the alpha position into its alcohol and corresponding carboxyllic acid.

vikash kumar

Btech. IIT Delhi