Chemoselective C(sp)–H borylation of terminal alkynes catalyzed by a bis(N-heterocyclicsilylene) manganese complex†
Abstract
The manganese(II) complex [Mn(SiNSi)Cl2] (SiNSi = 2,6-[EtNSi(NtBu)2CPh]2C5H3N) is an efficient catalyst for the chemoselective C(sp)–H borylation of terminal alkynes. Aliphatic and aromatic alkynes with different substituents have been efficiently borylated. Mechanistic studies indicate that the precatalyst enters the cycle by reaction with HBPin (Pin = pinacolate), which plays a key role in enabling a high chemoselective process.