N-Chlorosuccinimide/Sodium Hydroxide-Mediated Synthesis of Benzimidazoles from Amidines under Mild Conditions
摘要:
A convenient room-temperature one-pot procedure for the preparation of benzimidazoles derivatives from N-arylamidines has been developed. The reaction of N-aryl-N'-chloro amidines, generated by the treatment of N-arylamidines with N-chlorosuccinimide, in presence of sodium hydroxide provides benzimidazoles in good to excellent yields. Nitrogen anion generated in situ from succinimide (by-product of the chlorination step using NCS) and hydroxide anion was found to be highly effective as Bronsted base to promote the cyclization into benzimidazole of N-aryl-N'-chloroamidine.
Rh(III)-Catalyzed Synthesis of <i>N</i>-Unprotected Indoles from Imidamides and Diazo Ketoesters via C–H Activation and C–C/C–N Bond Cleavage
作者:Zisong Qi、Songjie Yu、Xingwei Li
DOI:10.1021/acs.orglett.5b03669
日期:2016.2.19
The synthesis of N-unprotected indoles has been realized via Rh(III)-catalyzed C–Hactivation/annulation of imidamides with α-diazo β-ketoesters. The reaction occurs with the release of an amide coproduct, which originates from both the imidamide and the diazo as a result of C═N cleavage of the imidamide and C–C(acyl) cleavage of the diazo. A rhodacyclic intermediate has been isolated and a plausible
Ruthenium(II)‐Catalyzed C−H Activation of Imidamides and Divergent Couplings with Diazo Compounds: Substrate‐Controlled Synthesis of Indoles and 3
<i>H</i>
‐Indoles
作者:Yunyun Li、Zisong Qi、He Wang、Xifa Yang、Xingwei Li
DOI:10.1002/anie.201606316
日期:2016.9.19
Indoles are an important structural motif that is commonly found in biologically active molecules. In this work, conditions for divergentcouplings between imidamides and acceptor–acceptor diazo compounds were developed that afforded NH indoles and 3H‐indoles under ruthenium catalysis. The coupling of α‐diazoketoesters afforded NH indoles by cleavage of the C(N2)−C(acyl) bond whereas α‐diazomalonates
Unaromatized Tetrahydrobenzimidazole Synthesis from <i>p</i>
-Benzoquinone and <i>N</i>
-Arylamidines and their Cytotoxic Potential
作者:Minh Quan Tran、Thanh Binh Nguyen、Wamtinga Richard Sawadogo、Ludmila Ermolenko、Sungmi Song、Pascal Retailleau、Marc Diederich、Ali Al-Mourabit
DOI:10.1002/ejoc.201801077
日期:2018.11.15
New tetrahydrobenzimidazoles were synthesized using a simple method from p‐benzoquinone and N‐arylamidines, and their cytotoxic potential was evaluated. Among them, three are cytotoxic in the µm range.
Synthesis of indoles and quinazolines <i>via</i> additive-controlled selective C–H activation/annulation of <i>N</i>-arylamidines and sulfoxonium ylides