acetates and sodiodimethylmalonate proceeds in high yields and enantioselectivities (up to 99% ee) using a diphenylphosphinoaryl oxazoline ligand. The so-formed substitution products are transformed into enantiomerically enriched succinicacids and also into enantiomerically enriched γ-lactones.
Merging Organocatalysis with an Indium(III)-Mediated Process: A Stereoselective α-Alkylation of Aldehydes with Allylic Alcohols
作者:Montse Guiteras Capdevila、Fides Benfatti、Luca Zoli、Marco Stenta、Pier Giorgio Cozzi
DOI:10.1002/chem.201001693
日期:——
be considered as a new frontier in the development of stereoselective reactions. An organocatalytic procedure mediated by the MacMillan imidazolidinone catalyst was coupled with an InBr3‐mediated process for the development of a novel stereoselective allylation reaction of aldehydes. Up to 98 % ee and up to 5:1 d.r. were obtained in the process.
Employing Arynes for the Generation of Aryl Anion Equivalents and Subsequent Reaction with Aldehydes
作者:Rahul N. Gaykar、Anup Bhunia、Akkattu T. Biju
DOI:10.1021/acs.joc.8b01549
日期:2018.9.21
a new synthetic strategy is demonstrated, where arynes are converted into aryl anionequivalents by treatment with phosphines and a base. The addition of phosphines to arynes form the phosphonium salts, which in the presence of a carbonate base generates the aryl anionequivalent. Subsequent addition of the aryl anions with aldehydes afforded the secondary alcohols.
The palladium-catalysed reductive addition of aryl iodides to propargyl alcohols: a route to /gg,/gg-diaryl allylic alcohols
作者:A. Arcadi、S. Cacchi、F. Marinelli
DOI:10.1016/s0040-4020(01)96756-0
日期:1985.1
The reaction of aryliodides with ethynyl and arylethynyl,dialky l carbinols in the presence of the tri- or dialkylammonium formate-palladium reagent provides a convenient route to γ,γ-diarylallylic alcohols. In the presence of arylethynyl,alkylcarbinols a lack of regioselectivity was observed and mixtures of ß,γ-, γ,γ-diarylallylic alcohols, and α,ß-unsatu rated ketones were obtained.
Substitution of allylic alcohols to form a carboncarbonbond is accomplished by a simple reaction of the allylic alcohol itself with an enoxysilane, catalyzed by [Ir(cod)(PPh3)2]X which is activated by H2 molecule. The anion part X of the complexes plays an important role to enhance the rate and product yields of the reactions. The efficacy of the catalyst increases with switching X in the order of