Oxidative Ring Opening of 1,3-Diarylbenzo[c]heterocycles Using m-CPBA: Preparation of 1,2-Diaroylbenzenes
作者:Meganathan Nandakumar、Ramakrishnan Sivasakthikumaran、Arasambattu K. Mohanakrishnan
DOI:10.1002/ejoc.201200311
日期:2012.7
An unprecedented oxidative cleavage of benzo[c]heterocyclesusingm-CPBA is reported. The reaction of 1,3-diaryl benzo[c]heterocycles with m-CPBA (meta-chloroperoxybenzoic acid) at room temperature for 5 min led to the formation of 1,2-diaroylbenzenes in good to excellent yields.
Regioselective Annulation of Unsymmetrical 1,2-Phenylenebis(diaryl/diheteroarylmethanol): A Facile Synthesis of Anthracene, Tetracene, and Naphtho[<i>b</i>]thiophene Analogues
作者:Ramakrishnan Sivasakthikumaran、Settu Muhammad Rafiq、Elumalai Sankar、J. Arul Clement、Arasambattu K. Mohanakrishnan
DOI:10.1002/ejoc.201501087
日期:2015.12
A systematic study on the regioselective cyclization of benzene- and naphthalene-based unsymmetrical diols with HBr (33 %) in acetic acid at room temperature led to the formation of annulation products. By using this method, synthesis of a wide variety of anthracene, tetracene and naphtho[b]thiopheneanalogues was achieved in good to excellent yields. By employing HBr (33 %) in acetic acid as a catalyst
Synthesis of Annulated Arenes and Heteroarenes Involving Lewis Acid-Mediated Regioselective Annulation of Unsymmetrical 1,2-(Diaryl/diheteroarylmethine)dipivalates
作者:Ramakrishnan Sivasakthikumaran、Meganathan Nandakumar、Arasambattu K. Mohanakrishnan
DOI:10.1021/jo301410w
日期:2012.10.19
A ZnBr2-mediated regioselectiveannulation of unsymmetrical 1,2-diarylmethinedipivalates in DCM at room temperature led to the formation of annulated arenes and heteroarenes. The annulation of the dipivalate proceeds through the intermediacy of benzylic carbocations followed by intramolecular cyclization and subsequent aromatization to give the annulated products. The annulation methodology is highly
室温下,DCM中ZnBr 2介导的不对称1,2-二芳基次甲基新戊二酸酯的区域选择性环化导致环化的芳烃和杂芳烃的形成。二戊酸酯的环化通过苄基碳阳离子的中间进行,然后进行分子内环化和随后的芳构化,以得到环化的产物。对于蒽和萘并[ b ]噻吩类似物的合成,环空方法学是非常有效的。
Copper-Catalyzed Benzylic C−H Oxygenation under an Oxygen Atmosphere via <i>N</i>-H Imines as an Intramolecular Directing Group
作者:Line Zhang、Gim Yean Ang、Shunsuke Chiba
DOI:10.1021/ol200425c
日期:2011.4.1
Copper-catalyzed benzylic C-H oxygenation under an oxygen atmosphere was developed starting from carbonitriles and Grignard reagents via N-H imine intermediates. The present process is characterized by the following two-step sequence in a one-pot manner: (1) addition of Grignard reagents to carbonitriles to form N-H imines and (2) benzylic C-H oxygenation (C=O bond formation) triggered by 1,5-hydrogen atom transfer with transient iminyl copper species.
Palladium-Catalyzed Acylation Reactions: A One-Pot Diversified Synthesis of Phthalazines, Phthalazinones and Benzoxazinones
作者:Basuli Suchand、Gedu Satyanarayana
DOI:10.1002/ejoc.201800159
日期:2018.5.24
proceeds through [Pd]‐catalyzed acylation and nucleophilic cyclocondensation with dinucleophilic reagents. This process was based on direct coupling with simple bench‐top aldehydes without the assistance of directing group and without activating the carbonyl group. The process is highly advantageous because it employs simple nitrogen‐based nucleophiles, and non‐toxic and readily accessible aldehydes as the