Copper-catalyzed cross-coupling of vinyliodonium salts and diboron reagents to generate alkenyl boronic esters

Abstract

<p>An efficient approach for the synthesis of alkenyl boronic esters through the copper-catalyzed cross-coupling of vinyliodonium salts and diboron reagents is reported. This method is distinguished by its mild condition...</p>

Copper‐Catalyzed Preparation of Alkenylboronates and Arylboronates

“…[164b] Recently in 2020, Shi group employed that CuI/PCy 3 combination to develop an efficient coppercatalyzed borylation method of vinyliodonium salts using symmetrical diboron reagents for rapid access to alkenylboronates (Scheme 31b). [165] The cross-coupling reactions of a variety of vinyl(aryl)iodonium salts with B 2 pin 2 resulted in various cyclic and acyclic (E-product, R 1 = H) alkenylboronates in moderate to good yields, however other diboron reagents (e. g. B 2 neop 2 , B 2 cat 2 , etc) were found less effective. Based on control experiments using TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl), the authors ruled out the possibility of a radical pathway, and an oxidative addition-reductive elimination mechanism was proposed.…”