Cobalt-Catalyzed (E)-β-Selective Hydrogermylation of Terminal Alkynes

A cobalt-catalyzed method for the hydrogermylation of alkynes is reported, providing a selective and accessible route to (E)-beta-vinyl(trialkyl)germanes from terminal alkynes and HGeBu3. As shown in multiple examples, the developed method demonstrates a broad functional group tolerance an practical utility for late-stage hydrogermylation of natural products. The method is compatible with alkynes bearing both aryl and alkyl substituents, providing unrivaled selectivity for previously challenging 1 degrees alkyl-substituted alkynes. Moreover, the catalyst used in this method, Co-2(CO)(8), is a cheap and commercially available reagent. Conducted mechanistic studies supported the syn-addition of Bu3GeH to an alkyne pi-complex.

Automated summary

A cobalt-catalyzed method has been developed for the hydrogermylation of alkynes, providing a selective and accessible route to (E)-beta-vinyl(trialkyl)germanes. The method demonstrates broad functional group tolerance and practical utility for late-stage hydrogermylation of natural products. Mechanistic studies support the syn-addition of Bu3GeH to an alkyne pi-complex.