Alkynylbis(alkylidynyl)phosphines: {LnM[triple bond, length as m-dash]C}2PC[triple bond, length as m-dash]CR

Abstract

Sequential treatment of [M(CBr)(CO)2(Tp*)] (M = Mo, W; Tp* = hydrotris(dimethylpyrazolyl)borate) with nBuLi, RPCl2 and LiCCSiMe3 affords [M{CPR(CCSiMe3)}(CO)2(Tp*)] (R = Ph, Cy) which are readily desilylated (TBAF) to provide the parent ethynyl derivatives [M{CPR(CCH)}(CO)2(Tp*)]. Alternatively, treating [W(CBr)(CO)2(Tp*)] with nBuLi, 1/2 PCl3 and LiCCR′ affords the alkynylbis(alkylidynyl)phosphines [R′CCP{CW(CO)2(Tp*)}2] (R′ = C6H5, C6H4Me-4, CMe3, SiMe3) and again the silyl derivative may be desilylated to the parent (R′ = H) which is readily converted to an arsino derivative (R′ = AsPh2). These novel architectures present new linkages for bridge-assisted polymetallic assembly. Show more