One-Pot Protocol for the Synthesis of Imidazoles and Quinoxalines using<i>N</i>-Bromosuccinimide
作者:Sachin D. Pardeshi、Pratima A. Sathe、Kamlesh S. Vadagaonkar、Atul C. Chaskar
DOI:10.1002/adsc.201700900
日期:2017.12.11
N‐bromosuccinimide (NBS)‐mediated one‐pot, green, efficient and practical synthesis of substituted imidazoles and quinoxalines has been achieved by the reaction of styrenes with N‐arylbenzamidines and o‐phenylenediamines, respectively, in a water:1,4‐dioxane mixture. The reaction involves formation of an α‐bromo ketone as an intermediate in the presence of NBS and water, followed by condensation with
Quinazolinones have broad applications in the biological, pharmaceutical and material fields. Studies on the synthesis of these compounds are therefore widely conducted. Herein, a novel and highly efficient copper-mediated tandem C(sp2)–H amination and annulation of benzamides and amidines for the synthesis of quinazolin-4(1H)-ones is proposed. This synthetic route can be useful for the construction of quinazolin-4(1H)-one
Vanadium-Catalyzed Oxidative C(CO)–C(CO) Bond Cleavage for C–N Bond Formation: One-Pot Domino Transformation of 1,2-Diketones and Amidines into Imides and Amides
作者:Chander Singh Digwal、Upasana Yadav、P. V. Sri Ramya、Sravani Sana、Baijayantimala Swain、Ahmed Kamal
DOI:10.1021/acs.joc.7b00950
日期:2017.7.21
identified that enables their transformation into imides and amides. The reaction proceeds by dual acylation of amidines via oxidative C(CO)–C(CO) bond cleavage of 1,2-diketones to afford N,N′-diaroyl-N-arylbenzamidine intermediates. In the reaction, these intermediates are easily hydrolyzed into imides and amides through vanadium catalysis. This method provides a practical, simple, and mild synthetic
Silver-catalyzed [3 + 2] domino reaction: an efficient strategy to synthesize imidazole-5-carbaldehydes
作者:Changcheng Wang、Hangqi Jiang、Weifeng Chen、Jun Dong、Zhengwang Chen、Hua Cao
DOI:10.1039/c7ob01242j
日期:——
An unprecedented regioselective silver-catalyzed [3 + 2] domino reaction of amidines and ynals for the formation of C–N bonds has been developed. The reaction provided a new route to prepare imidazole-5-carbaldehydes which are important intermediates for the construction of fine chemicals. The reaction proceeds smoothly with a broad range of substrates to give imidazoles in good yields.