planar chiral bifunctional phosphine compounds based on the [2.2]paracyclophane backbone with a pseudo-ortho substitution pattern have been synthesized and applied to the aza-Morita–Baylis–Hillman reaction. An enantiopure phosphine-phenol catalyst bearing an aryl group as a spacer connected to a phosphino group exhibited an exceptionally high reactivity (rt, 2–40 min) and good enantioselectivity (up to
作者:Christoph Zippel、Roumany Israil、Lars Schüssler、Zahid Hassan、Erik K. Schneider、Patrick Weis、Martin Nieger、Claudia Bizzarri、Manfred M. Kappes、Christoph Riehn、Rolf Diller、Stefan Bräse
DOI:10.1002/chem.202102341
日期:2021.11.2
The modular synthesis of Au(I)/Ru(II) decorated mono- and heterobimetallic complexes with π-conjugated [2.2]paracyclophane is described. [2.2]Paracyclophane serves as a rigid spacer which holds the metal centers in precise spatial orientations and allows metal-to-metal distance modulation. A broad set of architectural arrangements of pseudo -geminal, -ortho, -meta, and -para substitution patterns were
Planar Chiral Imidazolium Salts in the Asymmetric Rhodium-Catalyzed 1,2-Addition of Arylboronic Acids to Aldehydes
作者:Carsten Bolm、Thilo Focken、Jens Rudolph
DOI:10.1055/s-2005-861800
日期:——
Planarchiralimidazoliumsalts 8 and 13 were used as precursors for N-heterocycliccarbene ligands, which were applied in rhodium-catalyzed additions of arylboronic acids to aromatic aldehydes. With pseudo-ortho-disubstituted [2.2]paracyclophane (S,R p )-8b bearing a phosphinoyl substituent at the paracyclophane backbone, 38% ee has been achieved in this rather unexplored reaction.
Planar chiral aryl[2.2]paracyclophanyl-thioureas and -phosphine with a pseudo-ortho substitution pattern have been designed and efficiently synthesized by stepwise successive palladium-catalyzed crosscoupling reactions. (C) 2011 Elsevier Ltd. All rights reserved.