Transition-metal-promoted cyclization reactions of isocyanide ligands. Synthesis of cyclic aminooxycarbene complexes of platinum(II) and x-ray structure of trans-[(PPh3)2Pt[CN(C6H4Me-p)CH2CH2O]Br]BF4

Electrophilic isocyanide ligands in cationic Pt(II) and Pd(II) complexes of the type trans-[L2M(CNR)X]BF4 (I) (L = phosphine; R = alkyl, aryl; X = halide, Me) are converted to the five-membered cyclic diaminocarbene derivatives trans-(L2M[CN(R)CH2CH2N(H)]X)BF4 (II) by reaction with 2-bromoethylamine hydrobromide in the presence of n-BuLi.