Synthesis of homopropargyl alcohols via insertion of allenyl carbenoids into acyclic organozirconium bonds

Insertion of allenyl carbenoids (3-tosyloxy-1-lithioalk-1-ynes) into organozirconium complexes gave allenyl-zirconocenes via a 1,2-zirconate rearrangement. Trapping of the allenyl-zirconium species with aldehydes and ketones gave, after hydrolysis, a series of homopropargyl alcohols. Enantioenriched products were prepared by insertion of the lithium carbenoid derived from (S)-but-3-yn-2-yl 4-toluenesulfonate into alkyl- and alkenyl-chlorozirconocenes.