Syntheses of highly unsaturated isocyanidesvia organometallic pathways†
Dieter Lentz
Dalton Transactions Pub Date : 11/11/2011 00:00:00 , DOI:10.1039/C1DT11382H
Abstract

The carbon carbon coupling reaction by nucleophilic attack of (CO)5Cr(CN–CF[double bond, length as m-dash]CF2) 1 by lithium or Grignard compounds 2a–i yields the isocyanide complexes (CO)5Cr(CN–CF[double bond, length as m-dash]CF–R) 3a–i (a R = CH[double bond, length as m-dash]CH2, b R = CH[double bond, length as m-dash]CF2, c R = C[triple bond, length as m-dash]CH, d R = C[triple bond, length as m-dash]C–SiMe3, e R = C[triple bond, length as m-dash]C–Ph, f R = C[triple bond, length as m-dash]C–C6F4OMe, g R = C[triple bond, length as m-dash]C–C6H3(CF3)2, h R = C6F5, i R = C6H3(CF3)2) as mixtures of E and Z isomers. The dinuclear complexes 5a–c are obtained from the reaction of 1 with the dilithio or dimagnesium compound 4a–c as the Z,Z-, E,Z- and E,E-isomers, respectively. (CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)57 is obtained as a mixture of Z,Z-, Z,E- and E,E-isomers from (CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–H 3d by Eglington-Glaser coupling. (CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)56 and (CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)57 react with octacarbonyldicobalt forming the cluster compounds Z,Z-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}Co2(CO)6] Z,Z-8, E,Z-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}Co2(CO)6] E,Z-8 and E,E-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}Co2(CO)6] E,E-8 and Z,Z-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}{Co2(CO)6}2] Z,Z-9, E,Z-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}{Co2(CO)6}2] E,Z-9 and E,E-[{η22-(CO)5Cr(CN–CF[double bond, length as m-dash]CF–C[triple bond, length as m-dash]C–C[triple bond, length as m-dash]C–CF[double bond, length as m-dash]CF–NC)Cr(CO)5}{Co2(CO)6}2] Z,Z-9, respectively. The crystal and molecular structures of E-3d, Z-3h, Z,Z-8, E,Z-8 and Z,Z-9 were elucidated by single-crystal X-ray crystallography.

Graphical abstract: Syntheses of highly unsaturated isocyanidesvia organometallic pathways