Palladium-Catalyzed Vinylation of Cyclopentenes with Inverted Z,E-Isomerism of Vinylic Substrates

Org Lett. 2022 May 13;24(18):3373-3377. doi: 10.1021/acs.orglett.2c01131. Epub 2022 Apr 28.

Abstract

A palladium-promoted Mizoroki-Heck type reaction employing a directing-group strategy to efficiently produce the coupled vinyl cyclopentenes with excellent regio- and stereoselectivity is reported. Typically, a Pd-catalyzed reaction of 2-(cyclopent-2-en-1-yl)-N-tosylacetamide (1a) with (E)-styryl bromides gave cis-2-((Z)-styryl)cyclopent-3-en-1-yl-N-tosylacetamide (3e), an allylic substitution product. Interestingly, we have found that the E,Z-stereochemistry of vinylic substrates is inverted in those products. The mechanism of this catalytic reaction is discussed.