Stereospecificity in the rearrangement reactions of an N-phosphinoyl-O-sulfonylhydroxylamine with methylamine and tert-butylamine: retention of configuration at phosphorus as evidence for the initial formation of a phosphonamidic sulfonic mixed anhydride
作者:Martin J. P. Harger、Ramesh Sreedharan-Menon
DOI:10.1039/p19940003261
日期:——
possibility of a free metaphosphonimidate intermediate. For the MeNH2 reaction, the relative configurations of substrate and product, deduced from their X-ray crystal structures, show the sense of the stereospecificity to be retention of configuration at phosphorus; for the ButNH2 reaction, indirect evidence leads to the same conclusion. Retention of configuration is thought to result from initial base-induced
所述的反应Ñ -phosphinoyl- Ô(PH)(O)-sulfonylhydroxylamine PhMeCH P NHOMs 10与RNH 2(R = Me或卜吨)导致从磷的苯基的迁移到氮这导致重排产物PhMeCHP( O)(NHPh)NHR。使用富含一种非对映异构体(80:20)或另一种(3:97)的10种样品,与纯净RNH 2的反应具有高度立体特异性,从而排除了游离的偏亚膦酸酯中间体的可能性。对于MeNH 2反应中,从底物和产物的X射线晶体结构推断出其相对构型,显示出立体特异性的感觉,即保留了磷的构型。为卜牛逼NH 2反应,间接证据导致了同样的结论。构型的保留被认为是由于最初的碱基诱导的重排导致了膦酰胺磺酸混合酸酐PhMeCHP(O)(NHPh)OMs的转变,而磷的构型却发生了反转。然后用RNH 2进行亲核取代,得到所观察到的产物。亲核取代可具有缔合的S N2(P)机理(磷的构