Asymmetric assembly of aromatic rings to produce tetra-ortho-substituted axially chiral biaryl phosphorus compounds

Abstract

(Chemical Equation Presented) Densely substituted title compounds can be obtained efficiently through an enantioselective [2+2+2] cycloaddition catalyzed by a cationic RhI/H8-binap complex (see scheme). This method is highly practical in view of the ready access to substrates, mild reaction conditions, operational simplicity, and high catalytic activity. cod = 1,5-cyclooctadiene; H8-binap = 2,2′-bis(diphenylphosphanyl)-5, 5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl; Ts = p-toluenesulfonyl. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.