Open AccessA Proton-Switchable Bifunctional Ruthenium Complex That Catalyzes Nitrile Hydroboration
Author(s) -
Jacob B. Geri,
Nathaniel K. Szymczak
Publication year - 2015
Publication title -
journal of the american chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.115
H-Index - 612
eISSN - 1520-5126
pISSN - 0002-7863
DOI - 10.1021/jacs.5b08406
Subject(s) - chemistry , hydroboration , protonation , bifunctional , nitrile , ruthenium , pincer ligand , ligand (biochemistry) , catalysis , medicinal chemistry , pincer movement , proton , stereochemistry , organic chemistry , ion , biochemistry , receptor , physics , quantum mechanics
A new bifunctional pincer ligand framework bearing pendent proton-responsive hydroxyl groups was prepared and metalated with Ru(II) and subsequently isolated in four discrete protonation states. Stoichiometric reactions with H2 and HBPin showed facile E-H (E = H or BPin) activation across a Ru(II)-O bond, providing access to unusual Ru-H species with strong interactions with neighboring proton and boron atoms. These complexes were found to promote the catalytic hydroboration of ketones and nitriles under mild conditions, and the activity was highly dependent on the ligand's protonation state. Mechanistic experiments revealed a crucial role of the pendent hydroxyl groups for catalytic activity.