作者:Alois Fürstner、Günter Seidel
DOI:10.1055/s-1995-3854
日期:1995.1
Sodium deposited on inorganic supports such as Al2O3, TiO2 and NaCl (‘high-surface sodium’) is a cheap, readily prepared, nonpyrophoric reducing agent for TiCl3. The low-valent titanium thus obtained, after only 1 h reduction time, is well suited for McMurry coupling reactions, particularly of aromatic carbonyl compounds. It exhibits a previously unrivalled template effect for the cyclization of dicarbonyl compounds to (macrocyclic) cycloalkenes and is suitable for the reduction of N-acyl-2-aminobenzophenone derivatives to 2,3-disubstituted indoles. Even a 36-membered ring could be formed without recourse to high dilution techniques.
沉积在无机载体如Al2O3、TiO2和NaCl上的钠(“高表面积钠”)是一种廉价、易于制备且不易自燃的还原剂,可用于TiCl3。经过仅1小时的还原时间,获得的低价钛非常适合用于McMurry偶联反应,特别是芳香族羰基化合物的反应。它对于二羰基化合物环化为(大环)环烯烃展现出前所未有的模板效应,且适用于将N-酰基-2-氨基苯并酮衍生物还原为2,3-二取代的吲哚。甚至可以在不使用高稀释技术的情况下形成36元环。