MECHANISM OF THE EXCHANGE-REACTION OF HALODIAZIRINES WITH NUCLEOPHILES REVISITED - SYNTHESIS OF NEUTRAL, MONOCATIONIC OR DICATIONIC 4-16-MEMBERED PHOSPHORUS-HETEROCYCLES

Trimethyl-, diphenylmethyl-, triphenyl-, diphenylthienyl-, and bis(dim ethylamino) (isopropylthio)phosphine react with bromophenyldiazirine ( 1) giving cationic N,N'-bis(phosphine) adducts 2a-c, 7, and 8 in 83-95 % yields. Depending on the experimental conditions used, addition of 1 ,2-bis(diphenylphosphino)ethane to 1 leads to dicationic 14- and monoc ationic seven-membered heterocycles 3 (90% yield) and 4 (60% yield) or cationic N,N'-bis(diphosphine) adduct 5 (86% yield); similarly, when diphenyl(isopropylthio)phosphine is used, competitive reactions occur, leading to cationic five-membered heterocycle 9 (34% yield) and/or N, N'-Bis(diphosphine) adduct 10 (65% yield). 1,3-bis(diphenylphosphino)p ropane also reacts with 1, affording dicationic 16-membered heterocycl e 6 (75% yield). Addition of bis(diisopropylamino)(trimethylstannyl)ph osphine to 1 gives rise to a mixture of tannyl)imino]bis(diisopropylam ino)bromophosphorane (11) (32%), 2,2-bis(diisopropylamino)-4-phenyl-1, 3,2 lambda(5)-diazaphosphete (12) (26% yield), 1,3,5,2 lambda(5)-triaz aphosphinine 13 (3% yield), benzonitrile (35%), and bromotrimethylstan nane (60%). The mechanisms involved in these reactions are studied.