Oxidative addition of carbon-oxygen and carbon-nitrogen double bonds to WCl2(PMePh2)4. Synthesis of tungsten metallaoxirane and tungsten oxo- and imido-alkylidene complexes
作者:Jeffrey C. Bryan、James M. Mayer
DOI:10.1021/ja00162a034
日期:1990.3
WCl 2 L 4 (1, L=PMePh 2 ) reacts rapidly with a variety of ketones and aldehydes to form bis(η2 -ketone) or bis(η2 -aldehyde) complexes WCl 2 (η2 -O=CRR') 2 L 2 (2,3). When the ketone is part of a five-membered ring (cyclopentanone, 2-indanone, etc.), 2 rearranges with loss of ketone to give tungsten (VI) oxo-alkylidene products, W(O)(CRR')Cl 2 L 2 (4) in high yield. The net reaction is insertion
WCl 2 L 4 (1, L=PMePh 2 ) 与多种酮和醛快速反应形成双(η 2 -酮)或双(η 2 -醛)配合物WCl 2 (η 2 -O=CRR') 2 L 2 (2,3)。当酮是五元环(环戊酮、2-茚满酮等)的一部分时,2 重排失去酮得到钨 (VI) 氧代亚烷基产物,W(O)(CRR')Cl 2 L 2 (4) 高产。净反应是将钨中心插入酮碳氧双键中,这是一种四电子氧化加成。插入 N-环戊基-对甲苯胺的碳-氮双键产生类似的亚氨基-亚烷基配合物 W(N-Tol)[C(CH 2 ) 4 ]Cl 2 L 2
Radical cyclisations of imines and hydrazones
作者:W. Russell Bowman、Peter T. Stephenson、Nicholas K. Terrett、Adrian R. Young
DOI:10.1016/0040-4020(95)00412-2
日期:1995.7
Radical cyclisation of sp3 carbon-centred radicals onto imines and hydrazones provides a new method for the synthesis of 5- and 6-membered ring nitrogen heterocycles. Cyclisation onto the electrophilic carbon of the C=N group and 5-exo stereoelectronic selectivity are the dominating mechanistic parameters. The C-centred radical intermediates were generated from benzeneselenyl precursors using Bu3SnH