@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.}
}
@article {1500,
	title = {alpha-monodeuterated benzyl alcohols and phosphobetaines from reactions of aromatic aldehydes with a water/D2O-soluble phosphine},
	journal = {Inorganic Chemistry},
	volume = {45},
	number = {25},
	year = {2006},
	note = {ISI Document Delivery No.: 111UETimes Cited: 11Cited Reference Count: 49Moiseev, Dmitry V. James, Brian R. Hu, Thomas Q.},
	month = {Dec},
	pages = {10338-10346},
	type = {Article},
	abstract = {With the aim of learning more about the bleaching action of pulps by (hydroxymethyl) phosphines, we reacted several benzaldehydes, containing MeO, Me, OH, or halogen substituents, with tris(3-hydroxypropyl) phosphine, [HO(CH2)(3)](3)P, in aqueous solution at 90 degrees C under argon. Effective reduction of the aldehydes to the corresponding benzyl alcohols with concomitant oxidation of the phosphine to the phosphine oxide takes place, the reaction proceeding via an initially formed phosphonium species. When the reactions are carried out in D2O, the benzyl alcohol product from 3,4-dimethoxybenzaldehyde contains one deuterium atom at the benzyl-carbon atom, consistent with the last step of the mechanism involving a carbanion intermediate. With syringaldehyde (3,5-dimethoxy-4-hydroxy-benzaldehyde), the reduction product (syringyl alcohol) is more reactive toward the phosphine than is the starting aldehyde, and a zwitterionic, phosphobetaine product is formed. In D2O, the zwitterion benzyl protons and protons of the hydroxypropyl-CH2 adjacent to the P atom undergo H/D exchange via presumed phosphorus ylide intermediates. Under the same aqueous reaction conditions, tris(3-hydroxypropyl) phosphine, [HO(CH2)(3)](3)P (THPP), does not undergo redox reactions with aliphatic aldehydes but simply promotes a base-catalyzed self-condensation (aldol) reaction. THPP reduction of an aromatic ketone is sluggish, presumably because the carbonyl C-atom is less electrophilic than that present in an aromatic aldehyde.},
	keywords = {ALIPHATIC ALDEHYDES, BRIGHTNESS STABILIZING AGENTS, CONDENSATION REACTIONS, CRYSTAL-STRUCTURE, HYDROGENATION, LIGNIN MODEL COMPOUNDS, mechanical pulps, METHIDE, NUCLEOPHILIC-ADDITION, P-QUINONE, PHOSPHONIUM SALTS},
	isbn = {0020-1669},
	url = {<Go to ISI>://000242479700055},
	author = {Moiseev, D. V. and James, Brian R. and Hu, Thomas Q.}
}
@article {1500,
	title = {alpha-monodeuterated benzyl alcohols and phosphobetaines from reactions of aromatic aldehydes with a water / D2O-soluble phosphine},
	journal = {Inorganic Chemistry},
	volume = {45},
	number = {25},
	year = {2006},
	note = {ISI Document Delivery No.: 111UETimes Cited: 11Cited Reference Count: 49Moiseev, Dmitry V. James, Brian R. Hu, Thomas Q.},
	month = {Dec},
	pages = {10338-10346},
	type = {Article},
	abstract = {<p>With the aim of learning more about the bleaching action of pulps by (hydroxymethyl) phosphines, we reacted several benzaldehydes, containing MeO, Me, OH, or halogen substituents, with tris(3-hydroxypropyl) phosphine, [HO(CH2)(3)](3)P, in aqueous solution at 90 degrees C under argon. Effective reduction of the aldehydes to the corresponding benzyl alcohols with concomitant oxidation of the phosphine to the phosphine oxide takes place, the reaction proceeding via an initially formed phosphonium species. When the reactions are carried out in D2O, the benzyl alcohol product from 3,4-dimethoxybenzaldehyde contains one deuterium atom at the benzyl-carbon atom, consistent with the last step of the mechanism involving a carbanion intermediate. With syringaldehyde (3,5-dimethoxy-4-hydroxy-benzaldehyde), the reduction product (syringyl alcohol) is more reactive toward the phosphine than is the starting aldehyde, and a zwitterionic, phosphobetaine product is formed. In D2O, the zwitterion benzyl protons and protons of the hydroxypropyl-CH2 adjacent to the P atom undergo H/D exchange via presumed phosphorus ylide intermediates. Under the same aqueous reaction conditions, tris(3-hydroxypropyl) phosphine, [HO(CH2)(3)](3)P (THPP), does not undergo redox reactions with aliphatic aldehydes but simply promotes a base-catalyzed self-condensation (aldol) reaction. THPP reduction of an aromatic ketone is sluggish, presumably because the carbonyl C-atom is less electrophilic than that present in an aromatic aldehyde.</p>},
	keywords = {ALIPHATIC ALDEHYDES, BRIGHTNESS STABILIZING AGENTS, CONDENSATION REACTIONS, CRYSTAL-STRUCTURE, HYDROGENATION, LIGNIN MODEL COMPOUNDS, mechanical pulps, METHIDE, NUCLEOPHILIC-ADDITION, P-QUINONE, PHOSPHONIUM SALTS},
	isbn = {0020-1669},
	url = {<Go to ISI>://000242479700055},
	author = {Moiseev, D. V. and James, Brian R. and Hu, Thomas Q.}
}
