Tandem 6π-Azatriene Electrocyclization of Fused Amino-cyclopentenones: Synthesis of Functionalized Pyrrolo- and Indolo-quinoxalines
作者:Kapil Mohan Saini、Rakesh K. Saunthwal、Ankit Kumar、Akhilesh K. Verma
DOI:10.1021/acs.orglett.1c02782
日期:2021.10.1
A tandem 6π-azacyclization approach for the synthesis of diversified pyrrolo/indolo[1,2-a]quinoxalines from amino-cyclopentenones has been developed. The reaction proceeds through a trifluoroacetic-acid-mediated 6π-electrocyclization and concomitant opening of the cyclopentenone ring. The advantageous features of the developed chemistry include transition-metal-free conditions, operational simplicity
已经开发了一种用于从氨基环戊烯酮合成多样化吡咯并/吲哚[1,2- a ]喹喔啉的串联 6π-氮杂环化方法。该反应通过三氟乙酸介导的 6π-电环化和环戊烯酮环的伴随打开进行。所开发化学的优势特征包括无过渡金属条件、操作简单和广泛的底物范围。进一步的 X 射线晶体学研究证实了稠合杂环的指定结构。
Iodine-Mediated Solvent-Controlled Selective Electrophilic Cyclization and Oxidative Esterification of <i>o</i>-Alkynyl Aldehydes: An Easy Access to Pyranoquinolines, Pyranoquinolinones, and Isocumarins
作者:Akhilesh K. Verma、Vineeta Rustagi、Trapti Aggarwal、Amit P. Singh
DOI:10.1021/jo101526b
日期:2010.11.19
provides pyrano[4,3-b]quinolines 4a−f, via formation of cyclic iodonium intermediate Q; however, using alcohols as a solvent as well as nucleophile, o-alkynyl esters 5a−y were obtained selectively in good to excellent yields via formation of hypoiodide intermediate R. Subsequently, o-alkynyl esters were converted in to pyranoquinolinones 6a−i and isocoumarin 6j by electrophilic iodocyclization. This
Iodine-catalyzed and solvent-controlled selective electrophilic cyclization and oxidative esterification of ortho-alkynyl aldehydes
作者:Akhilesh Kumar Verma、Trapti Aggarwal、Vineeta Rustagi、Richard C. Larock
DOI:10.1039/b927185f
日期:——
4-Iodo-pyrano[4,3-b]quinolines and ortho-alkynyl esters were synthesized selectively from ortho-alkynyl aldehydes by an iodine-catalyzed and solvent controlled reaction.
Dual function of carbon tetrachloride: synthesis of chlorinated heterocycles
作者:Shiv Kumar、Rakesh K. Saunthwal、Kapil M. Saini、Akhilesh K. Verma
DOI:10.1039/c9cc04746h
日期:——
An efficient tandem approach to invent highly chlorinated and structurally diversified dihydropyridine fused heterocycles from easily accessible ortho-alkynylaldehydes and primary amines under metal-free conditions via four sequential bond formations is described. The proposed tandem route proceeds via a carbon tetrachloride-mediated 6-endo-dig ring closure followed by nucleophilic attack of the trichloromethyl
Triple‐Bond Directed Csp
<sup>2</sup>
−N Bond Formation with
<i>N</i>
‐Fluorobenzenesulfonimide as Aminating Source: One‐Step Transformation of Aldehydes into Amines
作者:Sushmita、Trapti Aggarwal、Norio Shibata、Akhilesh K. Verma
DOI:10.1002/chem.201903495
日期:2019.12.13
amination of ortho‐alkynyl quinoline/pyridine aldehydes using N‐fluorobenzenesulfonimide as nitrogen source under mild reaction conditions has been described. The designed reaction strategy was triggered by trapping of fluorine by base with subsequent attack of bis(phenylsulfonyl)‐λ2‐azane on the carbonyl carbon of a heterocycle, which was gradually converted into the corresponding amine through a Curtius