Ion Formation in MALDI: The Cluster Ionization Mechanism

A novel organoruthenium(III) amidinate, ((eta)5-C5Me5)RuCl((eta)-iPrN(eta)C(Me)NiPr) (2), has been prepared by oxidation of organoruthenium amidinate, ((eta)5-C5Me5)Ru((eta)-iPrN(eta)C(Me)NiPr) (1), by organic chlorides; both 1 and 2 are found to be good catalysts for atom-transfer cyclization of N-allyltrichloroacetamides which are useful for successful preparation of a pyrrolizidine alkaloid skeleton under mild conditions.