%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