51065-82-8Relevant articles and documents
Intramolecular nucleophilic displacement of halogen by phosphinate and thiophosphinate anions: Relative rates of formation of five- And six-membered rings 1
Chaudhry, Amirah,Hargcr, Martin J. P.,Shuff, Philippa,Thompson, Alison
, p. 1347 - 1352 (2007/10/03)
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)nCH 2(Ph)P(S)CT (n = 0,1) gives the products 16 (n = 0, 1) with the sulfur atom in the ring; the five-membered ring is now formed 30 times faster than the six, still a rather modest rate advantage.
Syntheses de phosphobetaines amphiphiles neutres a distances intercharge variables
Germanaud, Laurent,Brunel, Sylvian,Chevalier, Yves,Le Perchec, Pierre
, p. 699 - 704 (2007/10/02)
Neutral amphiphilic phosphonato- and phosphinatobetaines having different interionic distances are synthesized.Two paths for this synthesis have been studied. 2-(Ethoxy or phenyl) 2-oxo 1,2-oxaphospholanes react with lipophilic tertiary amines at 150 deg C, giving rise to mixtures of phosphobetaines and oxaphospholanate ammonium salts.Lewis acids increase the reaction rate but cannot change the selectivity.The specific production of phosphobetaines is achieved by a three steps sequence: the Arbusov reaction is applied to α,ο-dibromoalcanes and triethylphosphite or phenyldiethylphosphonite, providing ο-bromophosphonates in high yield.Tertiary amines are then condensed, followed by a bromide to hydroxide ions exchange on an anion exchange resin.Phosphobetaines are then specifically formed by thermal elimination of ethanol above the critical micellar concentration.Howewer, when Hoffmann elimination competes with basic hydrolysis of the phenylphosphinic ester groups, acidic hydrolysis is preferred, followed by neutralization with an OH- anion exchange resin.This preparative specific synthesis procedure affords pure, neutral and inorganic salt free zwitterionic compounds for a whole series of homologues.The physical properties of such compounds are believed to be designed upon the chice of the substituents (alkyl chain length, interionic methylene number, ethoxy or phenyl substituent at the phosphorous atom).
