Organophotoredox‐Catalyzed Cascade Radical Annulation of 2‐(Allyloxy)arylaldehydes with
<i>N</i>
‐(acyloxy)phthalimides: Towards Alkylated Chroman‐4‐one Derivatives
作者:Sanju Das、Sushanta Kumar Parida、Tanumoy Mandal、Laxmikanta Sing、Suman De Sarkar、Sandip Murarka
DOI:10.1002/asia.201901735
日期:2020.3.2
approach for the synthesis of highly important 3-alkyl substituted chroman-4-one scaffold is developed using visible light induced radicalcascade cyclization strategy. The reaction is initiated through the generation of alkyl radicals from N-(acyloxy)phthalimides under photoredox conditions, which subsequently undergo intermolecular cascaderadical cyclization on 2-(allyloxy)arylaldehydes to afford chroman-4-one
Copper-catalyzed synthesis of CN-containing chroman-4-ones via intramolecular radical cascade acyl-cyanation reaction
作者:Liang Wang、Min Jiang、Ming-qi Shi
DOI:10.1016/j.tetlet.2021.153061
日期:2021.5
A copper-catalyzed intramolecular radical cascade acyl-cyanation to synthesize cyano-containing chroman-4-ones has been developed. A series of CN-substituted chroman-4-one derivatives can be prepared with moderate to good yields using green cyano source under mild conditions. Control experiments indicated this reaction involved an intramolecular acyl radical addition/cyanation process. Moreover, this
structural skeletons. Herein, we report a visible-light-induced dual acylation of alkenes for constructing 3-substituted chroman-4-ones, which undergoes a radical tandem cyclization reaction through carbon–carbon bond cleavage of oxime esters by a nitrogen-centered radical strategy. A series of 3-substituted chroman-4-ones were prepared with up to 86% yield.
Regioselective Synthesis of Chromeno[4′,3′:4,5]pyrano[3,2-c][1,8]naphthyridin-13-one Derivatives by Domino Knoevenagel-Hetero-Diels-Alder Reactions
作者:K. Majumdar、Abu Taher、Sudipta Ponra
DOI:10.1055/s-0030-1260254
日期:2011.11
Efficientsynthesis of chromeno[4′,3′:4,5]pyrano[3,2-c][1,8]naphthyridin-13-one derivatives has been described by domino Knoevenagel-hetero-Diels-Alder reaction of 4-hydroxy-1-phenyl-1,8-naphthyridin-2(1H)-one with O-allylated/propargylated salicylaldehydes. The reaction occurs in a single step and is highlyregio- and stereoselective giving polycyclic heterocycles in high yields. 1,8-naphthyridine
色烯的有效合成[4',3':4,5]吡喃并[3,2- c ^ ] [1,8]萘啶-13-酮衍生物已经通过4-多米诺的Knoevenagel-杂Diels-Alder反应中所述羟基-1-苯基-1,8-萘啶-2(1 H)-1与O-烯丙基化/炔丙基化的水杨醛。该反应在单个步骤中发生,并且是高度区域和立体选择性的,从而以高收率得到多环杂环。 1,8-萘啶-Knoevenagel反应-杂-Diels-Alder反应-乙二胺二乙酸二铵-区域选择性-立体选择性-未活化的烯烃-未活化的炔烃
Visible light-induced radical cascade acylmethylation/cyclization of 2-(allyloxy)arylaldehydes with α-bromo ketones: access to cyclic 1,5-dicarbonyl-containing chroman-4-one skeletons
and efficient synthesis of cyclic 1,5-diketones containing chroman-4-one skeletons in moderate to good yields viaradicalcascade acylmethylation/cyclization of 2-(allyloxy)arylaldehydes with α-bromo ketones has been described. This reaction features a broad substrate scope, good functional group tolerance, and metal- and oxidant-free conditions. An acylmethyl radical-triggered cascade cyclization was