Formal Anti‐Markovnikov Addition of Water to Olefins by Titanocene‐Catalyzed Epoxide Hydrosilylation: From Stoichiometric to Sustainable Catalytic Reactions

Abstract

Here, the evolution of the titanocene-catalyzed hydrosilylation of epoxides that yields the corresponding anti-Markovnikov alcohols is summarized. The study focuses on aspects of sustainability, efficient catalyst activation, and stereoselectivity. The latest variant of the reaction employs polymethylhydrosiloxane (PMHS), a waste product of the Müller-Rochow process as terminal reductant, features an efficient catalyst activation with benzylMgBr and the use of the bench stable Cp 2 TiCl 2 as precatalyst. The combination of olefin epoxidation and epoxide hydrosilylation provides a uniquely efficient approach to the formal anti-Markovnikov addition of H 2 O to olefins.

Quaternary Carbon Synthesis by Titanocene Catalyzed Radical Allyl Transfer on Epoxides

“…Inspired by present synthetic targets in our group , in combination with our studies to develop novel titanocene catalyzed methodology, we initiated a study on enabling a radical allyl transfer reaction on epoxides, with the primary goal of generating quaternary carbon structures. Notably, while quaternary carbons are frequently encountered in complex natural products with important biological properties, such as Teupernin A ( 9 ), Leupyrrin A 1 ( 10 ), , and salimabromide ( 11 , Figure ), such hindered structural features still pose considerable synthetic challenges in complex target synthesis .…”