A Mild and Chemoselective Hydrosilylation of α‐Keto Amides by Using a Cs2CO3/PMHS/2‐MeTHF System. Issue 33 (10th July 2017)

• Record Type: Journal Article
• Authors: Kumar, Govindharaj; Muthukumar, Alagesan; Sekar, Govindasamy
• Is Part Of: European journal of organic chemistry. Issue 33(2017)
• Page Start: 4883
• Page End: 4890
• Publication Date: 2017-07-10
• Subjects: Chemoselectivity -- Hydrosilylation -- Reduction -- Ketones -- Green chemistry; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.201700374
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract : A Cs2 CO3 ‐catalyzed hydrosilylation reaction of α‐keto amides that proceeds through the in situ formation of MeSiH3 has been developed by using inexpensive polymethylhydrosiloxane in 2‐methyltetrahydrofuran (2‐MeTHF) as the solvent. A wide range of aryl and alkyl α‐keto amides, prepared from anilines and alkylamines, were subjected to the hydrosilylation conditions to afford α‐hydroxy amides in moderate to excellent yields. This transition‐metal‐free protocol was applied to a chemoselective hydrosilylation, in which reduction occurred at the carbonyl of the α‐keto amide functionality over that of the simple ketone, and further extended to a gram‐scale protocol. Abstract : A Cs2 CO3 ‐catalyzed chemoselective hydrosilylation of α‐keto amides to give structurally important mandelamides has been developed by using polymethylhydrosiloxane (PMHS) as the hydride source in 2‐methyltetrahydrofuran (2‐MeTHF), an eco‐friendly green solvent. A mechanistic study reveals the base‐catalyzed degradation of PMHS forms MeSiH3, the active species for the hydrosilylation process.