Cobalt-Catalyzed and Lewis Acid-Assisted Nitrile Hydrogenation to Primary Amines: A Combined Effort

The
selective hydrogenation of nitriles to primary amines using
a bench-stable cobalt precatalyst under 4 atm of H2 is
reported herein. The catalyst precursor was reduced in situ using
NaHBEt3, and the resulting Lewis acid formed, BEt3, was found to be integral to the observed catalysis. Mechanistic
insights gleaned from para-hydrogen induced polarization
(PHIP) transfer NMR studies revealed that the pairwise hydrogenation
of nitriles proceeded through a Co­(I/III) redox process.

本研究报道了在4个大气压的氢气环境下，利用一种实验室稳定的钴前催化剂对腈进行选择性加氢生成一级胺的过程。通过在原位使用NaHBEt3还原催化剂前体，形成的路易斯酸BEt3被发现对于所观察到的催化作用至关重要。从对亚氢诱导极化（PHIP）转移核磁共振研究中获得的机制见解揭示了腈的成对加氢过程是通过钴（I/III）氧化还原过程进行的。