- Double hydrophosphorylation of nitriles catalyzed by rare-earth-metal lanthanum
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A high-yielding and atom-efficient protocol for the double hydrophosphorylation of nitriles using a lanthanum-based N,N-dimethylbenzylamine complex (La(DMBA)3) as a precatalyst is reported. This method provides a straightforward and convenient
- Rina, Yesmin Akter,Schmidt, Joseph A.R.
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p. 14720 - 14729
(2020/11/13)
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- N-sulfonyl-and N-phosphorylbenzimidoylphosphonates
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A procedure for preparing N-sulfonyl-and N- phosphorylbenzimidoylphosphonates by oxidation of the corresponding α-(sulfonylamino)-and α-(phosphorylamino)benzylphosphonates was developed. The σ constants of imidoylphosphonate groups were evaluated by 19F NMR spectroscopy, and specific features of their electronic effects were considered. The reactions of the imidoylphosphonates obtained with O-, S-, P-, and N-nucleophiles were studied. The phosphonate-phosphoramidate rearrangement of α-aminobenzylidene-bisphosphonates was found. Nauka/Interperiodica 2006.
- Kolotilo,Sinitsa,Rassukanaya,Onys'ko
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p. 1210 - 1218
(2008/02/03)
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- Transformation of Arylmethylamines into α-Aminophosphonic Acids via Metalated Phosphoramidates: Rearrangement of Partly Configurationally Stable N-Phosphorylated α-Aminocarbanions
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N-Benzyl phosphoramidate was protected at nitrogen with a TMS, p-toluenesulfonyl, Boc, lithium carboxylate, or diethoxyphosphinyl group and metalated with s-BuLi or LDA at -78 °C at the benzylic carbon. For the latter three protecting groups, the intermediate α-amino(phenylmethyl)-lithiums isomerized to N-protected α-aminophosphonates (phosphoramidate-aminophosphonate rearrangement). (R)-N-[1-2H1]Phenylmethyl phosphoramidate in combination with Boc or (EtO)2P-(O) was used to demonstrate that metalation occurs with a high primary kinetic isotope effect (kH/kD 13-50) and migration of the diethoxyphosphinyl group with retention of configuration at carbon. Furthermore, the short-lived carbanion lithium pairs are partly configurationally stable as the aminophosphonates formed with the two protecting groups have enantiomeric excesses of 79 and 24%, respectively. When homochiral lithium amides derived from (R)-N-isopropyl-1-phenylethylamine and (R,R)-N,N-di(1-phenylethyl)amine were used to induce a phosphoramidate-aminophosphonate rearrangement, chiral nonracemic α-aminophosphonates were formed (ee 26-35%). Three racemic aminophosphonates were deprotected with hot 6 M HCl and purified by ion-exchange chromatography on Dowex 50W,H+ to exemplify the transformation of phenyl-, p-tolyl-, and (1′-naphthyl)methylamine into aminophosphonic acids via lithiated phosphoramidates.
- Hammerschmidt, Friedrich,Hanbauer, Martin
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p. 6121 - 6131
(2007/10/03)
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- Application of 1-azidoalkylphosphonates in the synthesis of phosphonodipeptides and other N-substituted aminophosphonates
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Efficient synthesis of diethyl 1-(isothiocyano)alkylphosphonates, and N-derivatives of diethyl 1-aminoalkylphosphonates as well as phosphonodipeptides were developed using diethyl 1-azidoalkylphosphonates as starting materials.
- Gajda, Tadeusz,Sikora, Dorota,Nonas, Tomasz
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p. 581 - 584
(2007/10/03)
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- PHOSPHORUS ANALOGUES OF AMINO ACIDS AND PEPTIDES XII. REACTION OF SODIUM DIETHYL PHOSPHITE WITH AROMATIC ALDAZINES AND HYDRAZONES
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The mechanism of the reaction of sodium diethyl phosphite with aromatic aldazines has been investigated.The initially formed monoaddition product (4) reacts with the excess of phosphorus reagent prior to the conceivable addition of diethyl phosphite to the C=N double bond.Cleavage of the N-N single bond is initiated by Single Electron Transfer from phosphite anion to the conjugated N=CH-Ph bond system.The scope of the reaction can be extended to other aromatic hydrazones.There is strong evidence to support the operation of a non-chain SET mechanism.
- Topolski, M.,Rachon, J.
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