One-Step Transformation of Carboxylic Acids into Aldehydes Induced by the Electrochemical Oxidation of Ph_3P

概要

論文の詳細を見る
Constant-current electrolysis (CCE) of Ph_3P and a carboxylic acid (RCO_2H, 1) in CH_2Cl_2 using a one-compartment cell equipped with two graphite plates as an anode and a cathode under a nitrogen atmosphere gave the corresponding aldehyde (2) when Ph_3P^+H・ClO^-_4 was used as a supporting electrolyte. The partial reduction was affected by the choice of electrolysis conditions, especially temperature and current density, depending on the structure of 1. Thus, the CCE of 1 with R=Ph-, o-Cl-Ph-, p-MeO-Ph-, Ph(CH_2)_2-, CH_3(CH_2)_8-, Ph_2CH-proceeded smoothly at -30℃ in fair yields. In the case of 1 with R=cyclo-C_6H_11- and (CH_3)_2CH-, the electrolysis had to be carried out under reflux, and with R=(CH_3)_3C- the aldehyde was obtained only in a poor yield even under reflux. Based on the results of cyclic voltammetry of the anolyte obtained by the CCE of CH_2Cl_2 solutions of Ph_3P, Ph_3P^+H・ClO^-_4,and 1 in a divided cell, the sequence of the partial reduction is proposed to be as follows : formation of acyloxy triphenylphosphonium ion (3) at the anode; the reaction of 3 with Ph_3P to afford the corresponding acyl triphenylphosphonium ion (4); reduction of 4 to the α-hydroxyalkyl triphenylphosphonium ion (7) at the cathode; decomposition of 7 to 2 and Ph_3P during the aqueous work-up after the CCE. The voltammetric study also suggested that the ease of the transformation of 3 to 4 is reflected in the required CCE conditions and may determine the yield of 2.
社団法人日本薬学会の論文
1994-05-15

One-Step Transformation of Carboxylic Acids into Aldehydes Induced by the Electrochemical Oxidation of Ph_3P

スポンサーリンク

概要

著者

関連論文

スポンサーリンク