for a range of aryl halide and boronate coupling partners. Notably, aryl chlorides are viable coupling partners even under relatively mild conditions at short reaction times (e.g., 1 h at 60 °C). One of the best catalysts described here exhibits improved turnover frequency for a particularly difficult coupling reaction involving an aryl chloride and a sterically congested boronicester.
已经开发了一系列具有酰胺,尿素和氨基甲酸酯骨架的新型单连接芳基四环复合物,发现它们对Suzuki-Miyaura交叉偶联具有很高的活性。这些Palladacycle预催化剂衍生自简单,廉价的原料,并且对空气和湿气稳定。在测试的那些中最活跃的同类物是基于尿素的palladacycles,它与t Bu 3一起使用。P配体可诱导一系列芳基卤和硼酸酯偶联伙伴的高转化率。值得注意的是,即使在相对温和的条件下,较短的反应时间(例如,在60°C下1 h),芳基氯化物也是可行的偶合伴侣。这里描述的最好的催化剂之一对于特别困难的偶合反应表现出改善的周转频率,所述偶合反应涉及芳基氯和空间拥挤的硼酸酯。
The Platinum Complex Catalyzed Reductive<i>N</i>-Carbonylation of Nitroarenes to the Carbamates
chloride and titanium(IV) chloride could be used as Lewis acids in place of tin(IV) chloride. Various nitroarenes were transformed into corresponding carbamate in moderate to excellent yields with the platinum catalyst.
铂催化剂与三苯基膦、氯化锡 (IV) 和三乙胺结合,在 180 °C 和 60 kg cm-2 的一氧化碳下,对硝基芳烃在乙醇中的还原性 N-羰基化显示出高活性。由硝基苯以83%的产率获得苯基氨基甲酸乙酯。氯化铁 (III)、氯化铝和氯化钛 (IV) 可用作路易斯酸代替氯化锡 (IV)。在铂催化剂的作用下,各种硝基芳烃以中等至极好的收率转化为相应的氨基甲酸酯。
Ultrasound Promoted ‘One Pot’ Conversion of Nitrocompounds to Carbamates
作者:S. Chandrasekhar、Ch. Narsihmulu、V. Jagadeshwar
DOI:10.1055/s-2002-25338
日期:——
An efficient ultrasound promoted novel direct conversion of nitro compounds to N-(tert-butoxycarbonyl) amines and N-(ethoxycarbonylamines) is achieved using Sn-NH4Cl for the first time.
An efficient one-pot synthesis of N,N′-disubstituted ureas and carbamates from N-acylbenzotriazoles
作者:Anoop S. Singh、Dhananjay Kumar、Nidhi Mishra、Vinod K. Tiwari
DOI:10.1039/c6ra14131e
日期:——
A facile and high-yielding one-pot synthesis of carbamates and N,N'-disubstituted symmetrical ureas from N-acylbenzotriazoles has been devised. It is believed that, the intermediate acyl-azide undergo Curtius rearrangement and under different...
An unprecedented zinc triflate catalyzed selective C-benzylation of anilides and heteroaryl amides with benzylchlorides having electron-donating group at para-position is reported. The protocol offers moderate to high yield of para-amido substituted diaryl and arylheteroarylmethanes, uses cheap and easily available benzylchlorides as the benzylating agent, catalytic amount of zinc triflate, and takes