title: 1,1,1,3,3,3-Hexafluoroisopropanol as a Remarkable Medium for Atroposelective Sulfoxide-Directed Fujiwara-Moritani Reaction with Acrylates and Styrenes.
abstract: Axially chiral biaryls are ubiquitous structural motifs of biologically active molecules and privileged ligands for asymmetric catalysis. Their properties are due to their configurationally stable axis, and therefore, the control of their absolute configuration is essential. Efficient access to atropo-enantioenriched biaryl moieties through asymmetric direct C-H activation, by using enantiopure sulfoxide as both the directing group (DG) and chiral auxiliary, is reported. The stereoselective oxidative Heck reactions are performed in high yields and with excellent atropo-stereoselectivities. The pivotal role of 1,1,1,3,3,3-hexafluoropropanol (HFIP) solvent, which enables a drastic increase in yield and stereoselectivity of this transformation, is evidenced and investigated. Finally, the synthetic usefulness of the herein disclosed transformation is showcased because the traceless character of the sulfoxide DG allows straightforward conversions of the newly accessed, atropopure sulfoxide-biaryls into several differently substituted axially chiral scaffolds.
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France.
authors.forename: Quentin
authors.initials: Q
authors.lastname: Dherbassy
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France.
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Schwertz
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France.
authors.forename: Matthieu
authors.initials: M
authors.lastname: Chessé
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France.
authors.forename: Chinmoy Kumar
authors.initials: CK
authors.lastname: Hazra
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France. wenceldelord@unistra.fr.
authors.forename: Joanna
authors.initials: J
authors.lastname: Wencel-Delord
authors.affiliation: Laboratoire de Chimie Moléculaire (UMR CNRS 7509), Université de Strasbourg, ECPM, 25 Rue Becquerel, 67087, Strasbourg, France. francoise.colobert@unistra.fr.
authors.forename: Françoise
authors.initials: F
authors.lastname: Colobert
keywords: C−H activation; asymmetric synthesis; chirality; fluorine; olefination