@article {2537,
	title = {Reactions of Tertiary Phosphines with Alcohols in Aqueous Media},
	journal = {Inorganic Chemistry},
	volume = {48},
	number = {1},
	year = {2009},
	note = {ISI Document Delivery No.: 388HUTimes Cited: 4Cited Reference Count: 29Moiseev, Dmitry V. Patrick, Brian O. James, Brian R.},
	month = {Jan},
	pages = {239-245},
	type = {Article},
	abstract = {The phosphines R2R{\textquoteright}P [R = R{\textquoteright} = Me, Et, Pr-n, Pr-i, (CH2)(3)OH; Me2PhP and MePh2P] react with 2- or 4-hydroxybenzyl alcohols, including "lignin-type" vanillyl, syringyl, and alpha-methylvanillyl alcohols, in a 1:1 ratio in aqueous media, to give zwitterionic phosphobetaine products; these on treatment with aq HCl form the corresponding phosphonium chlorides in good to excellent yields. The syringyl derivative [3,5-(OMe)(2)-4-OH-C6H2CH2PEt3]Cl was structurally characterized by X-ray analysis. Kinetically, the reactivity of the benzyl alcohols, studied with the water-soluble [HO(CH2)(3)](3)P, decreases with substituents in the order 2-hydroxy > 4-hydroxy > vanillyl > syringyl > alpha-methylvanillyl, while 3-hydroxybenzyl alcohol is unreactive; the trend is consistent with reactivity requiring the presence of an ortho- or para-OH substituent in the aromatic ring of the alcohol, and that the reactions proceed via a carbocation species stabilized as a quinone methide. Triethylphosphine reacts with coniferyl alcohol at the C=C moiety to give a zwitterionic intermediate that is again converted by aq HCl to a phosphonium chloride; no reaction was observed with cinnamyl alcohol. The effect on a phenolic pK(a) by incorporation of a phosphonium substituent is also measured.},
	keywords = {ALDEHYDES, BENZYL, FACILE SYNTHESIS, LIGNIN, PHOSPHONIUM SALTS, QUINONE METHIDE},
	isbn = {0020-1669},
	url = {<Go to ISI>://000262011700032},
	author = {Moiseev, D. V. and Patrick, B. O. and James, Brian R.}
}
