Catalyst-free regioselective synthesis of benzopyran-annulated thiopyrano[2,3-b]thiochromen-5-(4H)-one derivatives by domino-Knoevenagel-hetero-Diels–Alder reaction of terminal alkynes with 4-hydroxy dithiocoumarin in aqueous medium
作者:K.C. Majumdar、Abu Taher、Sudipta Ponra
DOI:10.1016/j.tetlet.2010.02.118
日期:2010.4
benzopyran-annulated thiopyrano[2,3-b] thiochromen-5(4H)-ones has been described by domino-Knoevenagel-hetero-Diels–Alder reaction of 4-hydroxy dithiocoumarin and O-propargylated salicylaldehyde in aqueousmedium and in the absence of any catalyst. The single step reaction is highly regioselective and provides polycyclic heterocycles in high yields.
通过多羟基-Knoevenagel-杂-Diels-4-羟基二硫代香豆素和O-炔丙基化的水杨醛的Alder反应描述了新型五环苯并吡喃环化的吡喃并[2,3 - b ] thiochromen-5(4 H)-的合成。水性介质,并且没有任何催化剂。一步反应是高度区域选择性的,并以高收率提供多环杂环。
Green Synthesis of Benzopyran-Annulated Thiopyrano[2,3-b]thiochromen-5(4H)-ones by Domino Knoevenagel-Hetero-Diels-Alder Reaction
作者:K. Majumdar、Abu Taher、Sudipta Ponra
DOI:10.1055/s-0030-1258261
日期:2010.12
Benzopyran-annulated thiopyrano[2,3-b]thiochromen-5(4H)-ones have been synthesized by the domino Knoevenagel-hetero-Diels-Alder (DKHDA) reaction of 4-hydroxydithiocoumarin with O-allylated salicylaldehyde and O-propargylated salicylaldehyde in aqueous medium. The reaction requires only a single step operation and is highly regio- and stereoselective providing potentially bioactive polycyclic heterocycles in high yields.
Wittig olefination and thiol mediated 7-endo-trig radical cyclization: novel synthesis of oxepin derivatives
作者:K.C. Majumdar、Abu Taher
DOI:10.1016/j.tetlet.2008.10.134
日期:2009.1
Thiophenol-mediated 7-endo radical cyclization for the synthesis of seven-membered cyclic ethers is described. This method can be successfully applied to synthesize various benzoxepin derivatives, which are present in many natural products as building blocks. Alkenyl radicals are generated from easily available terminal alkynes and thiophenol.
Catalyst-free domino-Knoevenagel-hetero-Diels–Alder reaction of terminal alkynes in water: an efficient one-step synthesis of indole-annulated thiopyranobenzopyran derivatives
作者:K.C. Majumdar、Abu Taher、Sudipta Ponra
DOI:10.1016/j.tetlet.2009.10.108
日期:2010.1
The domino-Knoevenagel-hetero-Diels–Alder reaction of O-propargylated salicylaldehyde and 1-methylindoline-2-thione in aqueous medium in the absence of Lewis acid has been described for the synthesis of hitherto unreported indole-annulated pentacyclic heterocyclescontaining oxygen, nitrogen and sulfur. This methodology involves only one step and easy work-up procedure to give the products in 72–80%
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