Palladium-catalyzed α,β-dehydrogenation of acyclic ester equivalents promoted by a novel electron deficient phosphinooxazoline ligand
作者:Tyler J. Fulton、Brenda Wu、Eric J. Alexy、Haiming Zhang、Brian M. Stoltz
DOI:10.1016/j.tet.2019.05.065
日期:2019.8
phosphinooxazoline (PHOX) ligand. The reaction proceeds from the Z-enol carbonate to provide dehydrogenation products exclusively in high E/Z selectivity, while the E-enol carbonate provides the α-allylation product with only minor dehydrogenation. The reaction proceeds with a broad scope of Z-enol carbonates derived from N-acyl indoles to furnish acyclic formal α,β-unsaturated ester equivalents.
Enantioselective construction of sterically hindered tertiary α-aryl ketones: a catalytic asymmetric synthesis of isoflavanones
作者:Michael P. Carroll、Helge Müller-Bunz、Patrick J. Guiry
DOI:10.1039/c2cc36452b
日期:——
A method for the catalyticasymmetric alpha-arylation of ketones bearing very sterically hindered aryl rings has been developed. This reaction occurs under mild conditions, in short reaction times and has been applied to the first catalyticasymmetricsynthesis of isoflavanones.
Rapid synthesis of an electron-deficient t-BuPHOX ligand: cross-coupling of aryl bromides with secondary phosphine oxides
作者:Nolan T. McDougal、Jan Streuff、Herschel Mukherjee、Scott C. Virgil、Brian M. Stoltz
DOI:10.1016/j.tetlet.2010.08.039
日期:2010.10
Herein an efficient and direct copper-catalyzed coupling of oxazoline-containing aryl bromides with electron-deficient secondary phosphine oxides is reported. The resulting tertiary phosphine oxides can be reduced to prepare a range of PHOX ligands. The presented strategy is a useful alternative to known methods for constructing PHOX derivatives. (C) 2010 Elsevier Ltd. All rights reserved.