Additions of anionic nucleophiles to carbonyl compounds: Cation and e-lectrophile nature influence on ionic association vs carbonyl complexation control

✍ Scribed by A. Loupy; M.C. Roux-Schmitt; J. Seyden-Penne

• Publisher: Elsevier Science
• Year: 1981
• Tongue: French
• Weight: 201 KB
• Volume: 22
• Category: Article
• ISSN: 0040-4039
• DOI: 10.1016/s0040-4039(01)90411-3

✦ Synopsis

SlJMM4RY : the reacticm of benzaldehyde with LiCH.fN in THF is controlled by carbonyl comple-x&ion while with KCH#N the reaction is controlled by ionic association. In the reaction of m.Cl.C6H4CHCN-/Lif with substituted benzaldehydes, carbonyl complexation prevails with p.CH30C$14CH0 while ionic association dominates with PhCHO and p.CNC6H4CH0. During the nucleophilic addition of anionic reagents to carbonyl compounds, the associated cation can induce two opposite kinetic effects (scheme I) : either a rate decrease due to interaction with the anion (case b)(ionic association) or a rate increase due to interaction with the carbonyl compounds (case c)(complexation)(l-3) a) N-+ -i:=o rate constant ko b) N-M+ +-k=O k. : k.