REGIOSPECIFIC REACTION OF PHOSPHAIMINES WITH A ZIRCONOCENE-BENZYNE COMPLEX - SYNTHESIS AND REACTIVITY OF NOVEL AZAPHOSPHAZIRCONAINDANS

Azaphosphazirconaindan systems (RCp)(2)ZrN(R(1))P(NR(2)R(3))(o-C6H4) 4 a (R = H) and 5a,b (R = t-Bu) are easily synthesized in a regiospecifi c way via a zirconocene-benzyne intermediate by means of thermolysis o f Cp(2)ZrMePh 1 or (t-BuCp)(2)ZrPh(2) 2 in the presence of phosphaimin es R(1)N = P-NR(2)R(3) (3a: R(1) = R(2) = R(3) = SiMe(3); 3b: R(1) = R (2) = t-Bu, R(3) = SiMe(3)). After selective reaction of elemental sul fur on the phosphorus atom, Zr-N and Zr-C bond cleavage occurs on trea tment with methanol, affording phosphine sulfides PhP(S)(NHR(1))(NHR(2 )) 8a,b. In these two reactions, complexes (t-BuCp)(2)ZrN(R(1))P(S)(NH R(2))(o-C6H4) 7a,b resulting from a selective cleavage of one N-SiMe(3 ) bond linked by the phosphorus atom can be isolated. With selenium po wder, similar behavior leads to complexes (t-BuCp)(2)ZrN(R(1))P(Se)(NH R(2))(o-C6H4) 10a,b.