Abstract:

Tri and tetrasubstituted alkenes are represented in bioactive compounds and organic materials and serve as valuable synthetic intermediates, including by transferring their stereochemical information onto asymmetric products. Current synthetic methodologies face limitations in achieving the regio- and stereodefined synthesis of these highly substituted alkenes. Herein we present the development of a novel mechanistically derived approach for generating highly substituted alkenes with regio- and stereocontrol. The concept of a modified electrophilic cyclization dealkylation mechanism was first investigated with B-chlorocatecholborane. The mechanistic concept was then expanded to iodination, making complementary alkene products. Finally, a conceptual leap was made to gold(I/III) catalyzed thioarylation reaction resulting in 2,3-dihydrothiopheniums. Concurrent mechanistic studies provided mechanistic insight and guided further improvements and expansions of this methodology.