220114-03-4Relevant articles and documents
Diastereoselective Synthesis of P-Chirogenic and Atropisomeric 2,2′-Bisphosphino-1,1′-binaphthyls Enabled by Internal Phosphine Oxide Directing Groups
Huo, Shangfei,Li, Jianli,Wang, Tingyi,Wang, Zeming,Xue, Qingquan,Zhu, Meifang,Zuo, Weiwei
supporting information, p. 8153 - 8159 (2020/04/24)
Diphosphine ligands that merge both axial and P-centered chirality may exhibit superior or unique properties. Herein we report the diastereoselective introduction of P-centered chirality at the 2-position of the axially chiral 2′-(phosphine oxide)-1,1′-binaphthyl scaffold. A lithium–bromide exchange reaction of a 2-bromo-2′-(phosphine oxide)-1,1′-binaphthyl and treatment with dichlorophosphines followed by a nucleophilic organometallic reagent afforded unsymmetrical 2-phosphino-2′-(phosphine oxide)-1,1′-binaphthyls with binaphthyl axial chirality and one or two phosphorus stereocenters with a variety of P substituents. The final diastereomerically pure 2,2′-bisphosphino-1,1′-binaphthyls were obtained by reduction of the phosphine oxide directing group. Preliminary results demonstrated that a ligand with this hybrid chirality could induce higher stereoselectivity in the metal-complex-catalyzed asymmetric hydrogenation of a dialkyl ketone.
