Mechanistic Insights into Transition Metal-Catalysed Oxidation of a Hydroxamic Acid within situ Diels–Alder Trapping of the Acyl Nitroso Derivative
作者:Judith A. K. Howard、Gennadiy Ilyashenko、Hazel A. Sparkes、Andrew Whiting、Allen R. Wright
DOI:10.1002/adsc.200700568
日期:2008.4.7
New insights into the mechanism for the transition metal-mediated oxidation of hydroxamic acids to give intermediate acyl nitroso species, with subsequent hetero-Diels–Alder trapping are presented. The activation of triphenylphosphine-ligated ruthenium-salen complexes is examined, and evidence is presented for the ruthenium-oxo species which are involved in the oxidative process of the hydroxamic acid
提出了新的见解,介绍了过渡金属介导的异羟肟酸氧化产生中间体酰基亚硝基物质的机理,以及随后的杂Diels-Alder捕集。研究了三苯基膦连接的钌-salen配合物的活化,并提供了涉及异羟肟酸氧化过程的钌-氧代物种的证据。解释了观察到的中间分子酰基亚硝基物种涉及的分子间环加成过程中缺乏不对称诱导的现象,并通过比较了钌-salen-基体系与亚硝基甲苯,铜(I)/铜(II)BINAP-催化的亚硝基吡啶配合物。