Enantioselective Acylation of Secondary Alcohols Catalyzed by Chiral N-Heterocyclic Carbenes
摘要:
The synthetic utility of chiral N-heterocyclic carbenes, which have been used mainly in transition metal-catalyzed reactions as a ligand, was demonstrated by the enantioselective acylation of secondary alcohols.
Thermalrearrangement of mono-, di-, and triphenyl-substituted ketene ethylene acetals was studied. Pyrolysis of all of these acetals provided phenyl-substituted tetrahydro-2-furanones as a major product. The more phenyl groups substitute on the ketene acetal skeleton, the lower reaction temperature was required for the rearrangement. In the cases of the diphenylketene acetals at high temperatures
Enantioselective Acylation of Secondary Alcohols Catalyzed by Chiral <i>N</i>-Heterocyclic Carbenes
作者:Taichi Kano、Kouji Sasaki、Keiji Maruoka
DOI:10.1021/ol050174r
日期:2005.3.1
The synthetic utility of chiral N-heterocyclic carbenes, which have been used mainly in transition metal-catalyzed reactions as a ligand, was demonstrated by the enantioselective acylation of secondary alcohols.
Regio‐ and Stereoselective Chan‐Lam‐Evans Enol Esterification of Carboxylic Acids with Alkenylboroxines
作者:Luuk Steemers、Linda Wijsman、Jan H. van Maarseveen
DOI:10.1002/adsc.201800914
日期:2018.11.5
Efficient and scalable Cu(II)‐mediated enol esterification methodology of carboxylicacids from alkenyl boroxines and boronic acids is presented. The reaction shows a wide scope in aliphatic and aromatic carboxylicacids in combination with several alkenyl boroxines. In the case of 2‐substituted alkenyl boroxines the double bond configuration was fully retained in the enol ester product. Also N‐hydroxyimides