Synthesis of Conjugated Boron‐Enynes via cis‐Alkynylboration of Terminal Alkynes

Abstract A unique and practical Cu‐catalyzed cis‐ alkynylboration of terminal alkynes with diboron reagents and bromoalkynes has been realized. This process enables the convenient synthesis of a large variety of trisubstituted enynylboronates under mild reaction conditions with broad functional‐groups compatibility, high regioselectivity and stereoselectivity. The usability and practicability of this process was further demonstrated by the successful modular synthesis of enediynes. magnified image