CHEMISTRY OF HETERO-ALLENE AND HETERO-ALLYLIC DERIVATIVES WITH RHODIUM .1. REACTION OF RHODIUM(I)-HETERO-ALLYLIC COMPOUNDS WITH HETERO-ALLENES .A. ISOTHIOCYANATES

The reaction of the rhodium(I) complexes Rh[X-C(Z)-Y](PPh3)2, in which [X-C(Z)-Y]- is an unsaturated hetero-allylic chelate coordinating via two of the three hetero atoms (X, Y, Z = N, P or S), with an excess of the hetero-allene molecule RNCS (R = Ph, Me) leads to the formation of the isocyanide-dithiocarbonimidato complexes Rh[X-C(Z)-Y](RNC)(RNCS2)(PPh3)2 by disproportionation reaction proceeds in three consecutives steps. Initially a cumulene molecule is coordinated side-on by the CS double bond to Rh. This is followed by attack of the carbon atom of a second hetero-allene at the endocyclic nucleophile of the moeity. © 1979.