Modular and Selective Access to Functionalized Alkynes and Allenes via the Intermediacy of Propargylic Acetates

We report an efficient one-pot, two-step procedure for the modular synthesis of alpha-difunctionalized alkynes and trisubstituted allenes by sequential cross-coupling of benzal gem-diacetates with organozinc or -copper reagents in the absence of external transition metals. The intermediacy of propargylic acetates enables the divergent and selective synthesis of these valuable products. This method features its readily accessible substrates, relatively mild conditions, wide scope, and scalability in practical synthesis.

Automated summary

We present an efficient one-pot, two-step procedure for synthesizing alpha-difunctionalized alkynes and trisubstituted allenes using benzal gem-diacetates and organozinc or -copper reagents without external transition metals. The presence of propargylic acetates allows for the selective synthesis of these valuable products. This method is advantageous due to its accessible substrates, mild conditions, broad applicability, and scalability in practical synthesis.