N-BENZOYL ISOCYANIDE GROUP - PI-ACCEPTOR LIGAND SIMILAR TO CARBON-MONOXIDE AND A NEW ROUTE TO OPTICALLY-ACTIVE CHROMIUM(0) COMPLEXES

The photochemical synthesis of [(arene)Cr(CO)2CN] derivatives from (arene)Cr(CO)3 complexes in the presence of KCN, followed by electrophilic attack of benzoyl chloride on the cyanide ligand, affords benzoyl isocyanide complexes of the type (arene)Cr(CO)2(CNCOPh). The spectroscopic properties (13C NMR and IR) of these compounds are discussed by comparision with derivatives of the type (arene)Cr(CO)2L (L = CO, CS, CNCH3, P(OPh)3). These results suggest that N-acyl isocyanides have electronic properties close to those of carbon monoxide. Specific photochemical substitution of CO by P(OPh)3 in (arene)Cr(CO)2(CNCOPh) confirms the substantial strength of the Cr°―CNCOPh bond and provides a new route to chiral complexes. Two pairs of optically active diastereoisomers, [formula omitted] have been prepared as synthetic applications of the latter reaction. © 1979, American Chemical Society. All rights reserved.