85231-92-1Relevant articles and documents
New protocol for converting alcohols into amines
Klepacz,Zwierzak
, p. 1683 - 1689 (2007/10/03)
The reactions between diethyl N-(t-butoxycarbonyl)phosphoramidate 1, diisopropyl azodicarboxylate (DIAD), triphenylphosphine (TPP) and primary or secondary alcohols lead to the corresponding diethyl N-alkyl-N-(t-butoxycarbonyl)phosphoramidates 2a-o. Deprotection of crude 2 by refluxing with p-toluenesulfonic acid monohydrate in ethanol affords ammonium tosylates 3a-o in moderate to good overall yields. The N-alkylation of 1 proceeds stereoselectively with complete inversion of the configuration of the alkyl group.
Transformation of Arylmethylamines into α-Aminophosphonic Acids via Metalated Phosphoramidates: Rearrangement of Partly Configurationally Stable N-Phosphorylated α-Aminocarbanions
Hammerschmidt, Friedrich,Hanbauer, Martin
, p. 6121 - 6131 (2007/10/03)
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.
An optimized version of Gabriel-type nucleophilic amination
Zwierzak, Andrzej
, p. 2287 - 2293 (2007/10/03)
N-Alkylation of primary alkyl bromides with diethyl N-sodio-N-(t- butoxycarbonyl)phosphoramidate 1 carried out in boiling acetonitrile in the presence of 10mol% of tetrabutylammonium bromide as catalyst leads to the corresponding N-alkyl derivatives 2a-I. Deprotection of 2 by refluxing with p-toluenesulfonic acid in ethanol-affords ammonium tosylates 3a-I in reasonable yields.
Conversion of Alcohols into Primary Amines, a New Mitsunobu Version of Gabriel-type Synthesis
Slusarska, Elzbieta,Zwierzak, Andrzej
, p. 402 - 405 (2007/10/02)
Primaere und sekundaere Alkohole liefern die entsprechenden Amin-hydrochloride 3 mit guten Ausbeuten (60-85percent), wenn sie unter milden Bedingungen mit N-(Diethoxyphosphoryl)-carbamidsaeure-tert-butylester (1) in Gegenwart von Azodicarbonsaeure-diethylester/Triphenylphosphan umgesetzt und danach die entstandenen N-Alkyl-N-(diethoxyphosphoryl)carbamidsaeureester 2 mit gasfoermigem HCl gespalten werden.Die Stereochemie dieser Reaktion wird untersucht.
