A Universal Organocatalyst for Selective Mono-, Di-, and Triboration of Terminal Alkynes

Multiboronate compounds are valuable synthetic buildingblocksfor the construction of complex organic architectures via cross-couplingchemistry at the C-B bonds. Hence, there has been a tremendousamount of work in the past decades to develop practical multiborationreactions. Many of the developed methods start from alkynes, the mostversatile synthetic precursors for multiboronates, and use transition-metalcomplexes as catalysts. However, several drawbacks such as low efficiency,poor selectivity, and narrow substrate and catalyst scopes remainmajor challenges to be addressed in this research area. Herein, wereport the development of a universal organocatalytic system to promotethe mono-, di-, and triboration of terminal alkynes in a highly efficientand selective manner. The reaction outcomes can be manipulated atwill by varying the catalyst loading, reagent stoichiometry, and reactiontime. A combined computational and experimental mechanistic studyoffers interesting insights into the selectivity of these sequentialreactions.