10.1021/ja043884l.s002 David A. Nicewicz David A. Nicewicz Jeffrey S. Johnson Jeffrey S. Johnson Three-Component Coupling Reactions of Silylglyoxylates, Alkynes, and Aldehydes:  A Chemoselective One-Step Glycolate Aldol Construction American Chemical Society 2005 diol adduct diastereoselectivitie presence ee silylgyloxylate terminal alkynes Aldehyde variety functionalized zinc acetylide chemoselective manner Construction aldehyde methylephedrine unoptimized acetonide Chemoselective deprotection glycolate sequence yield Alkyne Silylglyoxylate Aldol dr ZnI 2 Et 3 N Mechanistic experiments Glycolate silylglyoxylate aldol 2005-05-04 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Three_Component_Coupling_Reactions_of_Silylglyoxylates_Alkynes_and_Aldehydes_A_Chemoselective_One_Step_Glycolate_Aldol_Construction/3288052 A single-pot three-component coupling reaction of silylglyoxylates (<b>1</b>), terminal alkynes, and aldehydes in the presence of ZnI<sub>2</sub> and Et<sub>3</sub>N is presented. The products of the reaction, densely functionalized silyl-protected glycolate aldols (<b>2</b>), can be converted to the corresponding acetonides (<b>3</b>) 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 (<b>1</b>) in a chemoselective manner. Using an unoptimized (+)-<i>N</i>-methylephedrine and Zn(OTf)<sub>2</sub> system, silyl-deprotected adduct <b>2</b> was formed in 64% ee and 89:11 dr.