Evolution of a ‘privileged’ P-alkene ligand: added planar chirality beats BINOL axial chirality in catalytic asymmetric C–C bond formation

Abstract

Planar chirality is introduced in a ‘privileged’ P-alkene phosphoramidite ligand and shown to overwhelm the chirality of the BINOL auxiliary.

Dibenzoazepine hydrazine is a building block for N-alkene hybrid ligands: exploratory syntheses of complexes of Cu, Fe, and Li

“…nacnac type ligands) have different electronic properties through the second hydrazine nitrogen atom. 5 Some time ago, we and others have introduced 5 H -dibenzo[ b , f ]azepine as a building block for the synthesis of chiral 6 and achiral 7 hemilabile P - and S -alkene hybrid ligands (Chart 1): Ligands I and II feature both point and planar chirality, while the superbulky ligand IV displays a crystallographic Tolman cone angle of 229°. In order to extend the versatility of this building block we envisaged the corresponding hydrazine 5 H -dibenzo[ b , f ]azepin-5-amine ( 2 ) inspired by Grützmacher's 5-amino-5 H -dibenzo[ a , d ]cycloheptene (tropNH 2 ).…”