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Catalytic, enantioselective sulfenylation of ketone-derived enoxysilanes.
J Am Chem Soc. 2014 Sep 17; 136(37):13016-28.JA

Abstract

A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases-tertiary amines, sulfides, and selenophosphoramides-were identified as active catalysts for the α-sulfenylation reaction. Among a wide variety of chiral Lewis bases in all three classes, only chiral selenophosphoramides afforded α-phenylthio ketones in generally high yield and with good enantioselectivity. The selectivity of the reaction does not depend on the size of the silyl group but is highly sensitive to the double bond geometry and the bulk of the substituents on the double bond. The most selective substrates are those containing a geminal bulky substituent on the enoxysilane. Computational analysis revealed that the enantioselectivity arises from an intriguing interplay among sterically guided approach, distortion energy, and orbital interactions.

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Authors+Show Affiliations

Denmark SE
Roger Adams Laboratory, Department of Chemistry, University of Illinois , Urbana, Illinois 61801, United States.
Rossi S
No affiliation info available
Webster MP
No affiliation info available
Wang H
No affiliation info available

MeSH

CatalysisEthersKetonesLewis BasesSilanesStereoisomerismSulfamerazine

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

25192220

Citation

Denmark, Scott E., et al. "Catalytic, Enantioselective Sulfenylation of Ketone-derived Enoxysilanes." Journal of the American Chemical Society, vol. 136, no. 37, 2014, pp. 13016-28.
Denmark SE, Rossi S, Webster MP, et al. Catalytic, enantioselective sulfenylation of ketone-derived enoxysilanes. J Am Chem Soc. 2014;136(37):13016-28.
Denmark, S. E., Rossi, S., Webster, M. P., & Wang, H. (2014). Catalytic, enantioselective sulfenylation of ketone-derived enoxysilanes. Journal of the American Chemical Society, 136(37), 13016-28. https://doi.org/10.1021/ja506133z
Denmark SE, et al. Catalytic, Enantioselective Sulfenylation of Ketone-derived Enoxysilanes. J Am Chem Soc. 2014 Sep 17;136(37):13016-28. PubMed PMID: 25192220.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Catalytic, enantioselective sulfenylation of ketone-derived enoxysilanes. AU - Denmark,Scott E, AU - Rossi,Sergio, AU - Webster,Matthew P, AU - Wang,Hao, Y1 - 2014/09/05/ PY - 2014/9/6/entrez PY - 2014/9/6/pubmed PY - 2015/11/10/medline SP - 13016 EP - 28 JF - Journal of the American Chemical Society JO - J Am Chem Soc VL - 136 IS - 37 N2 - A catalytic, enantioselective, Lewis base-catalyzed α-sulfenylation of silyl enol ethers has been developed. To avoid acidic hydrolysis of the silyl enol ether substrates, a sulfenylating agent that did not require additional Brønsted acid activation, namely N-phenylthiosaccharin, was developed. Three classes of Lewis bases-tertiary amines, sulfides, and selenophosphoramides-were identified as active catalysts for the α-sulfenylation reaction. Among a wide variety of chiral Lewis bases in all three classes, only chiral selenophosphoramides afforded α-phenylthio ketones in generally high yield and with good enantioselectivity. The selectivity of the reaction does not depend on the size of the silyl group but is highly sensitive to the double bond geometry and the bulk of the substituents on the double bond. The most selective substrates are those containing a geminal bulky substituent on the enoxysilane. Computational analysis revealed that the enantioselectivity arises from an intriguing interplay among sterically guided approach, distortion energy, and orbital interactions. SN - 1520-5126 UR - https://www.unboundmedicine.com/medline/citation/25192220/Catalytic_enantioselective_sulfenylation_of_ketone_derived_enoxysilanes_ DB - PRIME DP - Unbound Medicine ER -