The development and application of ruthenium catalysed oxidations of a hydroxamic acid and in situ Diels–Alder trapping of the acyl nitroso derivative
作者:Kevin R. Flower、Andrew P. Lightfoot、Hayley Wan、Andrew Whiting
DOI:10.1039/b206430h
日期:——
11%). Ruthenium( II) salen complexes also catalyse the oxidation of N-Boc-hydroxylamine in the presence of TBHP, to give the N-Boc-nitroso compound which can be efficiently trapped with a range of dienes. However, use of an enantiopure ruthenium salen complex does not produce asymmetric induction via the trapping of the intermediate acyl nitroso dienophile with cyclohexadiene, which strongly suggests
钌( II)配合物可用于氧化 N -Boc-羟胺 在......的存在下 叔丁基过氧化氢 (TBHP)转化为相应的亚硝基双亲物, 环己-1,3-二烯作为杂Diels–Alder加合物。已经获得了直接干预的证据。三苯基氧化膦稳定的钌( IV)氧代-络合物作为催化活性物质。手性双齿双膦衍生钌的用途配体(BINAP或PROPHOS)导致极低的不对称感应(8%和11%)。钌( II)沙伦络合物还可以在TBHP存在下催化N -Boc-羟胺的氧化 ,得到 N -Boc-亚硝基化合物,该化合物可以有效地被一系列二烯捕获。但是,使用对映纯的钌salen配合物不会通过捕获中间体而产生不对称感应 酰基 亚硝基亲二烯体与 环己二烯,这强烈表明中间体在Diels–Alder环加成之前很容易从参与氧化步骤的手性钌络合物中解离。