Synthesis of 2-Boryl Allylboronates by a Bimetallic Platinum/Zinc-Promoted Diborylation of Propargylic Amines

2-Boryl allylboronates, which contain both a C(sp(2))-B bond and a C(sp(3))-B bond, are attractive synthetic intermediates due to their diverse reactivity profiles toward a wide range of organic transformations. We report a facile approach to (Z)-2-boryl allylboronates through a Pt/Zn-promoted diborylation reaction of readily available propargylic amines. An array of valuable (Z)-2-boryl allylboronates were obtained in up to 73% yield in the presence of 2.5 mol% of Pt(PPh3)(4) and 50 mol% of ZnBr2.