Reversible double insertion of aryl isocyanates into the Ti–O bond of titanium(IV) isopropoxide
作者:Rajshekhar Ghosh、Munirathinam Nethaji、Ashoka G. Samuelson
DOI:10.1016/j.jorganchem.2004.11.038
日期:2005.3
The insertion of phenyl isocyanate into titanium isopropoxide leads to the formation of a dimeric complex [Ti(OiPr)2(μ-OiPr)C6H5N(OiPr)CO}]2 (1) which has been structurally characterized. Reaction of titanium isopropoxide with two and more than 2 equiv. of phenyl isocyanate is complicated by competitive, reversible insertion between the titanium carbamate and titanium isopropoxide. The ligand formed
苯基异氰酸酯的插入异丙醇钛导致的形成的二聚复合物钛[Ti(O我PR)2(μ-O我PR)C 6 H ^ 5 N(0我PR)CO}] 2(1),其已经在结构上得到了表征。异丙醇钛与两个或大于2当量的反应 氨基甲酸钛和异丙醇钛之间竞争性,可逆的插入使异氰酸苯酯的合成变得复杂。通过将异氰酸苯基酯插入氨基甲酸钛中形成的配体已在结构上以其质子化形式C 6 H 5 N C(O i Pr)O} C(O)N(H)C进行了表征6 H 5(3aH)。动力学上有利于氨基甲酸酯的插入,而异丙醇中的热力学上有利的产物。
Copper-catalyzed carbonylation of anilines by diisopropyl azodicarboxylate for the synthesis of carbamates
been developed. The N–H bond cleavage and N–C bond formation were notably achieved under solvent-free conditions and a variety of carbamates were synthesized from readily available anilines using diisopropyl azodicarboxylate (DIAD) as the carbonylating source.