SOME INSERTION REACTIONS OF THE MN-C BOND OF CYCLOMANGANATED TRIPHENYLPHOSPHINE CHALCOGENIDES

The complex Ph2P(S)C6H4Mn(CO)(4) (Ib) reacts with alkenes CH2=CH-R (R = COOMe, CN, C(O)Me) in refluxing MeCN or MeOH to give substituted der ivatives of Ph3P=S with a CH2CH2R group introduced in the ortho positi on of one phenyl ring. Other species are also formed including -(2-dip henylthiophosphinyl)phenyl)-2-buten-2-amine (characterised by an X-ray structure determination) from the reaction of 1b with CH2=CHCN in MeC N. In contrast, reaction with alkynes C-2(COOMe)(2) or C2H(COOMe) allo wed isolation of the new seven-membered metallocycle arising from inse rtion of the alkyne into the Mn-C bond of lb. All three Ph2P(E)C6H4Mn( CO)(4) (E=0, S, Se) readily insert SO2; a structure determination of t he product with E=Se shows a six-membered metallocyclic ring which inc orporates five different elements. (C) 1998 Elsevier Science S.A.