Electrophilic amination of racemic and non-racemic allenyltitaniums. One-pot synthesis of α-hydrazinoalkynes from propargylic alcohol derivatives

Article abstract of DOI:10.1016/S0040-4039(99)00584-5

Successive treatment of propargylic carbonates or phosphates with a Ti(O-i-Pr)₄/2i-PrMgCl reagent and dialkyl azodicarboxylates gave α- hydrazinoalkynes in good yields. The reaction, which proceeded with up to 86% chiral transfer, thus has opened up a new route to optically active α- hydrazinoalkynes from the optically active propargylic compounds.