Intramolecular nucleophilic displacement of halogen by phosphinate and thiophosphinate anions: relative rates of formation of five- and six-membered rings 1
作者:Amirah Chaudhry、Martin J. P. Harger、Philippa Shuff、Alison Thompson
DOI:10.1039/a900623k
日期:——
Intramolecular nucleophilic substitution transforms the phosphinate anions XCH2CH2(CH2)nCH2(Ph)P(O)O– (n = 0, 1; X = Br, Cl) (Et3NH+ salts; CH2Cl2 solution) into cyclic phosphinate esters 14 (n = 0, 1); unusually the five-membered ring product (n = 0) is formed only 4.3 (X = Br) or 5.7 (X = Cl) times faster than the six (n = 1). The analogous cyclisation of the thiophosphinate anions ClCH2CH2(CH2)nCH2(Ph)P(S)O–