Iridium Catalysts with f-Amphox Ligands: Asymmetric Hydrogenation of Simple Ketones

Abstract

A series of modular and rich electronic tridentate ferrocene aminophosphoxazoline ligands (f-amphox) have been successfully developed and used in iridium-catalytic asymmetric hydrogenation of simple ketones to afford corresponding enantiomerically enriched alcohols under mild conditions with superb activities and excellent enantioselectivities (up to 1 000 000 TON, almost all products up to >99% ee, full conversion). The resulting chiral alcohols and their derivatives are important intermediates in pharmaceuticals.

From Mechanistic Study to Chiral Catalyst Optimization: Theoretical Insight into Binaphthophosphepine-catalyzed Asymmetric Intramolecular [3 + 2] Cycloaddition

“…To better illustrate the steric repulsion in different regions of the binaphthophosphepine catalysts, a 2D contour map along the z -axis of the van der Waals surface of catalyst ( S ) -1a was plotted 92–95 , which is shown in Fig. 11a.…”

Catalysis, kinetics and mechanisms of organo-iridium enantioselective hydrogenation-reduction

“…Pathway A involves a direct hydrogen transfer proceeding by means of simultaneous interaction of the substrate and hydrogen donor with the metal centrethe close proximity of these two entities results in a concerted delivery of a formal hydride from the alcohol donor to the acceptor ketone. 98,99 This pathway does not involve a metal hydride as the hydride is provided by the donor alcohol. The metal's purpose is to aid enhancement of the electrophilic nature of the carbonyl, making it more receptive to the hydride attack and providing a highly organised transition state where the correct orientations for bond making and breaking are met.…”

Enzyme‐Inspired Chiral Secondary‐Phosphine‐Oxide Ligand with Dual Noncovalent Interactions for Asymmetric Hydrogenation

“…Zuschriften of 2a using our previously developed f-amphox ligand, [15] in situ lactonization occurred to afford the chiral lactone 5 with the syn-configuration in high yield and excellent ee and d.r. (Scheme 4b).…”