A convenient oxidative cyclodesulfurization method toward the synthesis of benzofused nitrogen heterocycles using inexpensive and readily available potassium periodate as an oxidant was developed. Upon treating isothiocyanates with ortho-substituted anilines bearing N,N-, N,O-, and N,S-bis-nucleophiles, followed by an intramolecular cyclization of the in situ generated monothioureas, substituted 2-aminobenzazole
Preparation of Fused Tetracyclic Quinazolinones by Combinations of Aza-Wittig Methodologies and Cu<sup>I</sup>-Catalysed Heteroarylation Processes
作者:Juan Antonio Bleda、Pilar M. Fresneda、Raul Orenes、Pedro Molina
DOI:10.1002/ejoc.200900082
日期:2009.5
A number of linear quinazolinonesfused to five-membered rings – benzimidazo[2,1-b]quinazolinones 8 and benzothiazolo[2,3-b]quinazolinones 10 – have been prepared from iminophosphoranes 4, derived from N-substituted o-azidobenzamides by a combination of the aza-Wittigmethodology and Cu I -catalysed heteroarylation. The presence of a nitrogen functionality in the N-aryl substituent of 4 promotes heterocyclization
simple and efficientsynthesis of 11H-pyrido[2,1-b]quinazolin-11-ones by Cu(OAc)2·H2O-catalyzed reaction of easily available substituted isatins and 2-bromopyridine derivatives has been developed. The reaction involves C–N/C–C bond cleavage and two C–N bond formations in a one-pot operation. This methodology is complementary to previously reported synthetic procedures, and two plausible reaction mechanisms
Serendipitous Synthesis of Pyridoquinazolinones <i>via</i> an Oxidative C–C Bond Cleavage
作者:Matthias Brendel、Priyanka R. Sakhare、Gaurav Dahiya、Parthasarathi Subramanian、Krishna P. Kaliappan
DOI:10.1021/acs.joc.0c00982
日期:2020.6.19
A direct one-pot copper-catalyzed oxidative C–C bond cleavage route to the synthesis of pyridoquinazolinones is described. This one-pot strategy involves a copper-catalyzed C–N coupling followed by concomitant C(sp3)–H oxidation and amidation via oxidative C–C bond cleavage under an O2 atmosphere to deliver the target molecules in high yields.
Copper-catalyzed domino sequences: a new route to pyrido-fused quinazolinones from 2′-haloacetophenones and 2-aminopyridines
作者:Phuc H. Pham、Son H. Doan、Ngan T. H. Vuong、Vu H. H. Nguyen、Phuong T. M. Ha、Nam T. S. Phan
DOI:10.1039/c8ra03744b
日期:——
A new pathway to access pyrido-fused quinazolinones via a Cu(OAc)2-catalyzed domino sequential transformation between 2′-haloacetophenones and 2-aminopyridines was demonstrated. The solvent and base exhibited a remarkable effect on the transformation, in which the combination of DMSO and NaOAc emerged as the best system. Cu(OAc)2·H2O was more active towards the reaction than numerous other catalysts
证明了通过2'-卤代苯乙酮和 2-氨基吡啶之间的 Cu(OAc) 2催化多米诺连续转化获得吡啶并稠合喹唑啉酮的新途径。溶剂和碱对转化效果显着,其中DMSO和NaOAc的组合是最佳体系。 Cu(OAc) 2 ·H 2 O 比许多其他催化剂对反应更具活性。这种方法是新的,将补充以前合成吡啶并稠合喹唑啉酮的方案。