1313743-01-9Relevant academic research and scientific papers
Catalytic, Enantioselective Sulfenylation of Ketone-Derived Enoxysilanes
Denmark, Scott E.,Rossi, Sergio,Webster, Matthew P.,Wang, Hao
supporting information, p. 13016 - 13028 (2015/09/15)
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 Br?nsted 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.
Catalytic asymmetric addition of thiols to nitrosoalkenes leading to chiral non-racemic α-sulfenyl ketones
Hatcher, John M.,Kohler, Mark C.,Coltart, Don M.
, p. 3810 - 3813 (2011/09/16)
The first asymmetric organocatalytic sulfenylation of in situ derived nitrosoalkenes leading to chiral nonracemic α-sulfenylated ketones is described. The transformation proceeds in an umpolung fashion, relative to enolate/azaenolate methods, and uses simple thiols, thereby obviating the need for electrophilic sulfur reagents.
