New Methods in Organic Synthesis Through Copper-Catalyzed Borylation Reactions: Stereoselective Synthesis of 1,4-Diols and Vinylboronates

Abstract

Boronic acid derivatives have become important intermediates in organic and medicinal chemistry and, as a result, the ­development of new methods that permit the efficient creation of C–B bonds under mild conditions has become an active field of research in organic synthesis. In the last ten years, copper-catalyzed borylation reactions have emerged as versatile new tools for introducing boron atoms into organic molecules. Here, we describe our recent research in this field. We have developed two copper-­catalyzed borylation reactions. The first involves the SN2′ addition of bis(pinacolato)diboron to allylic epoxides. This reaction permits the stereoselective synthesis of a wide range of compounds containing a 1,4-diol moiety, a fragment that is present in many natural products with important biological activities. The second reaction is a copper-catalyzed formal carboboration process. In this reaction, a C–B and a C–C bond are created in a single catalytic cycle, and the method provides a new tool for the synthesis of tri- and tetrasubstituted vinylboronates. 1 Introduction 2 Stereoselective Synthesis of 1,4-Diols 3 Synthesis of Tri- and Tetrasubstituted Vinylboronates 4 Outlook