Base‐Modulated 1,3‐Regio‐ and Stereoselective Carboboration of Cyclohexenes

Abstract

Abstract While chain‐walking stimulates wide interest in both polymerization and organic synthesis, site‐ and stereoselective control of chain‐walking on rings is still a challenging task in the realm of organometallic catalysis. Inspired by a controllable chain‐walking on cyclohexane rings in olefin polymerization, we have developed a set of chain‐walking carboborations of cyclohexenes based on nickel catalysis. Different from the 1,4‐ trans ‐selectivity disclosed in polymer science, a high level of 1,3‐regio‐ and cis ‐stereoselectivity is obtained in our reactions. Mechanistically, we discovery that the base affects the reduction ability of B 2 pin 2 and different bases lead to different catalytic cycles and different regioselective products (1,2‐ Vs 1,3‐addition). This study provides a concise and modular method for the synthesis of 1,3‐disubstituted cyclohexylboron compounds. The incorporation of a readily modifiable boronate group greatly enhances the value of this method, the synthetic potential of which was highlighted by the synthesis of a series of high‐valued commercial chemicals and pharmaceutically interesting molecules.