%0 Journal Article
%A Nicewicz, David A.
%A Johnson, Jeffrey S.
%D 2005
%T Three-Component Coupling Reactions of Silylglyoxylates, Alkynes, and
Aldehydes: A Chemoselective One-Step Glycolate Aldol Construction
%U https://acs.figshare.com/articles/journal_contribution/Three_Component_Coupling_Reactions_of_Silylglyoxylates_Alkynes_and_Aldehydes_A_Chemoselective_One_Step_Glycolate_Aldol_Construction/3288052
%R 10.1021/ja043884l.s002
%2 https://acs.figshare.com/ndownloader/files/5125789
%K diol
%K adduct
%K diastereoselectivitie
%K presence
%K ee
%K silylgyloxylate
%K terminal alkynes
%K Aldehyde
%K variety
%K functionalized
%K zinc acetylide
%K chemoselective manner
%K Construction
%K aldehyde
%K methylephedrine
%K unoptimized
%K acetonide
%K Chemoselective
%K deprotection
%K glycolate
%K sequence
%K yield
%K Alkyne
%K Silylglyoxylate
%K Aldol
%K dr
%K ZnI 2
%K Et 3 N
%K Mechanistic experiments
%K Glycolate
%K silylglyoxylate
%K aldol
%X A single-pot three-component coupling reaction of silylglyoxylates (1), terminal alkynes, and aldehydes in the presence of ZnI2 and Et3N is presented. The products of the reaction, densely functionalized silyl-protected glycolate aldols (2), can be converted to the corresponding acetonides (3) in a one-pot deprotection/ketalization sequence. A variety of terminal alkynes and aldehydes can be successfully employed to give a range of highly functionalized, fully protected 1,2-diols in good yields and moderate diastereoselectivities. Mechanistic experiments suggest that the zinc acetylide reacts with the silylgyloxylate (1) in a chemoselective manner. Using an unoptimized (+)-N-methylephedrine and Zn(OTf)2 system, silyl-deprotected adduct 2 was formed in 64% ee and 89:11 dr.
%I ACS Publications