Preparation of Various Carboxylic Acid Esters from Bulky Alcohols and Carboxylic Acids by a New Type Oxidation-reduction Condensation Using 2,6-Dimethyl-1,4-benzoquinone
A new-type oxidation-reduction condensation by using 2,6-dimethyl-1,4-benzoquinone (DMBQ), carboxylic acids and in situ formed alkoxydiphenylphosphines (1) including the bulky alkoxy group-substituted ones proceeded smoothly to afford the corresponding carboxylic acidesters in good to high yields. Alkoxydiphenylphosphines were formed in situ by treating either N,N-dimethylaminodiphenylphosphine (Ph2PNMe2)
Kinetic resolution of racemicsecondaryalcohols has been achieved by the reaction with benzoyl halide in the presence of a SnX2-chiraldiaminecomplex to afford the corresponding benzoate in good to excellent enantioselectivities.
Direct Transacylation of 2,2,2-Trihaloethyl Esters with Amines and Alcohols Using Phosphorus(III) Reagents for Reductive Fragmentation and in Situ Activation
作者:Jeremy J. Hans、Russell W. Driver、Steven D. Burke
DOI:10.1021/jo991711m
日期:2000.4.1
reductants, with resultant carboxylate activation as an acyloxyphosphonium intermediate, and in situ trapping by amine or alcohol nucleophiles. Secondary and tertiary amides were synthesized, including a dipeptide, in good yields using hexamethylphosphorous triamide (Me2N)3P, as reducing agent. Optimal yields of esters derived from primary and secondary alcohols were obtained using tributylphosphine
作者:Andranik Petrosyan、Luisa Zach、Tobias Taeufer、T. S. Mayer、Jabor Rabeah、Jola Pospech
DOI:10.1002/chem.202201761
日期:2022.10.12
Pyrimidopteridine organic photoredox catalysts are applied in a formal addition of carboxylic acids to activated alkenes as a dual photoredox and hydrogen atom transfer catalysts. Electron-rich alkenes counter the decarboxylation of carboxylic acids upon single-electron oxidation and a selective hydroacetoxylation is observed.