Aluminum trichloride catalyzes the ring opening of a 1-chlorophosphirane W(CO)5 complex and its reaction with thiophene and ferrocene to give the corresponding 1-(2-thienyl)- and 1-ferrocenylphosphirane derivatives. The W(CO)5 complex of the 1-ferrocenylphosphirane is an efficient precursor of the phosphinidene complex [FcP-W(CO)5], which is trapped by tolan, trans-stilbene, and water. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.