Regioselective Hydrosilylation of Propargylic Alcohols: An Aldol Surrogate

Abstract

Aldol products from a non‐aldol reaction: A one‐pot protocol effects hydrosilylation of propargyl alcohols and subsequent oxidative cleavage to yield β‐hydroxy ketones in a chemo‐, regio‐, and enantioselective fashion. Further structural elaboration of the intermediate γ‐hydroxyvinylsilane is possible before the carbonyl group is unmasked (see scheme).

An Alkyne Hydrosilylation-Oxidation Strategy for the Selective Installation of Oxygen Functionality

“…The wealth of oxidation chemistry available from vinylsilane intermediates led us to consider the use of alkyne hydrosilylation together with vinylsilane oxidation 9-12 to introduce functionality distal to a hydroxyl group, which could control regio-and stereochemistry. 7 In this paper, we provide a full account of these regioselective hydrosilylations and the use of these adducts as an equivalent of an aldol, homo-aldol, and bishomo-aldol process. BDMS = benzyldimethylsilyl.…”

A regio- and stereoisomeric study of allylic alcohol fluorination with a range of reagents

“…This generated 5b as the major isomer, but with low diastereoselectivity (de 9%, determined by chiral GC-FID). A similar reaction was explored under non-chelation conditions using titanium tri-isopropoxychloride, to promote anti-selective addition [14] as illustrated in Scheme 2. This gave 5a in much higher diastereoisomeric excess (de 62%, determined by chiral GC-FID).…”

γ-Hydroxy-α,β-acetylenic esters: asymmetric syntheses and applications

“…The conjugated acetylenic and ester groups make the β-position of the propiolate susceptible to the nucleophilic addition of the amine. When these two groups are separated by methylene groups, the corresponding propargylic alcohol can be obtained with high enantioselectivity and good yield (Scheme 11) [32].…”