Highly Selective Hydroboration of Alkenes, Ketones and Aldehydes Catalyzed by a Well‐Defined Manganese Complex

Abstract

Well-defined manganese complexes based on inexpensive, readily available ligands, 2,2':6',2''-terpyridine and its derivatives have been prepared and employed for the selective hydroboration of alkenes, ketones and aldehydes. Highly Markovnikov regioselective hydroboration of styrenes as well as excellent chemoselective hydroboration of ketones over alkenes were achieved, for the first time, by an earth-abundant manganese catalyst.

Homogeneous Catalysis by Manganese‐Based Pincer Complexes

“…The groups of Zhang and Zheng developed the terpyridine‐based manganese complex 27 for the selective hydroboration of carbonyl compounds and alkenes . A variety of ketones and aldehydes were hydroborated with 1 equiv.…”

Cobalt‐Catalyzed Regioselective Hydroboration of Terminal Alkenes

“…The vast majority of known nonprecious metal catalysts have been found to promote the hydroboration of terminal alkenes with anti‐Markovnikov selectivity. However, a few catalysts based on earth‐abundant metals were recently shown to promote the unusual Markovnikov alkene hydroboration . Following reports of Cu I catalysts, our group reported the first manganese‐catalyzed hydroboration of terminal alkenes with Markovnikov selectivity in 2016 .…”

“…However, a few catalysts based on earth‐abundant metals were recently shown to promote the unusual Markovnikov alkene hydroboration . Following reports of Cu I catalysts, our group reported the first manganese‐catalyzed hydroboration of terminal alkenes with Markovnikov selectivity in 2016 . In the same year, nickel and iron complexes with N‐heterocyclic carbene (NHC) ligands were reported to catalyze the Markovnikov hydroboration of a range of aromatic terminal alkenes ,.…”

Interconverting Lanthanum Hydride and Borohydride Catalysts for C=O Reduction and C−O Bond Cleavage

“…[2f,h, 3c] Early trivalent lanthanide hydrides often provide high catalytic activity. [6] While hydroboration of aldehydes and ketones is catalyzed by alarge number of metal complexes, [7] fewer catalysts,m ainly magnesium [2f, 4, 8] and molybdenum compounds, [9] mediate hydroboration of esters. [6] While hydroboration of aldehydes and ketones is catalyzed by alarge number of metal complexes, [7] fewer catalysts,m ainly magnesium [2f, 4, 8] and molybdenum compounds, [9] mediate hydroboration of esters.…”