Cobalt-Catalyzed 1,1-Diboration of Terminal Alkynes: Scope, Mechanism, and Synthetic Applications.

ABSTRACT: A cobalt-catalyzed method for the 1,1-diboration of terminal alkynes with bis(pinacolato)diboron (B₂Pin₂) is described. The reaction proceeds efficiently at 23 °C with excellent 1,1-selectivity and broad functional group tolerance. With the unsymmetrical diboron reagent PinB-BDan (Dan = naphthalene-1,8-diaminato), stereoselective 1,1-diboration provided products with two boron substituents that exhibit differential reactivity. One example prepared by diboration of 1-octyne was crystallized, and its stereochemistry established by X-ray crystallography. The utility and versatility of the 1,1-diborylalkene products was demonstrated in a number of synthetic applications, including a concise synthesis of the epilepsy medication tiagabine. In addition, a synthesis of 1,1,1-

SUBMITTER: Krautwald S 

PROVIDER: S-EPMC5697746 | biostudies-literature | 2017 Mar

REPOSITORIES: biostudies-literature