25559-41-5Relevant academic research and scientific papers
Tetrahydrobenzochromene Synthesis Enabled by a Deconjugative Alkylation/Tsuji-Saegusa-Ito Oxidation on Knoevenagel Adducts
Navaratne, Primali V.,Grenning, Alexander J.
, p. 4566 - 4570 (2018)
A modular and practical route to versatile cyano-1,3-dienes by a sequence involving deconjugative alkylation and "Tsuji-Saegusa-Ito oxidation" is reported. In this letter, the versatility of the products is also explored, including a route to benzochromene scaffolds common to many natural products.
Cascade Claisen and Meinwald Rearrangement for One-Pot Divergent Synthesis of Benzofurans and 2 H-Chromenes
Song, Liyan,Su, Qian,Lin, Xi,Du, Zhihui,Xu, Huiyou,Ouyang, Ming-An,Yao, Hongliang,Tong, Rongbiao
supporting information, p. 3004 - 3009 (2020/04/20)
A new cascade approach has been developed for the one-pot four-step divergent synthesis of polysubstituted benzofurans and 2H-chromenes, featuring a novel cascade aromatic Claisen rearrangement/Meinwald rearrangement/dehydrative or oxidative cyclization. This new method was demonstrated with 39 examples tolerating different substitutions at an epoxide, allylic ether, and aromatic ring, and we showcased its utility with the first total synthesis of natural product liparacid A in seven steps.
A cascade Claisen rearrangement/o-quinone methide formation/electrocyclization approach to 2H-chromenes
Song, Liyan,Huang, Fang,Guo, Liwen,Ouyang, Ming-An,Tong, Rongbiao
supporting information, p. 6021 - 6024 (2017/07/10)
A new approach has been developed for the synthesis of 8-substituted 2H-chromenes, featuring a novel cascade aromatic Claisen rearrangement/o-quinone methide formation/6π-electrocyclization. This new method was demonstrated with 28 examples tolerating different substitutions at alkenes, allylic and aromatic ring and with total syntheses of three 2H-chromene natural products.
One-pot synthesis, biological evaluation, and docking study of new chromeno-annulated thiopyrano[2,3-c]pyrazoles
Parmar, Bhagyashri D.,Sutariya, Tushar R.,Brahmbhatt, Gaurangkumar C.,Parmar, Narsidas J.,Kant, Rajni,Gupta, Vivek K.,Murumkar, Prashant R.,Sharma, Mayank Kumar,Yadav, Mange Ram
, p. 639 - 657 (2016/07/12)
Abstract: A one-pot synthesis of new chromeno-annulated thiopyrano[2,3-c]pyrazoles has been achieved through a domino-Knoevenagel–hetero-Diels–Alder reaction after combining various pyrazol-5-thiones with O-alkenyloxy/alkynyloxy-salicylaldehydes/naphthaldehydes in a Br?nsted acidic ionic liquid, [Hmim]HSO4, methylimidazolium hydrogen sulphate, under microwave irradiation. The method is simple and in many cases the isolated products did not require further purification. The central pyranothiopyranyl cis-fusion was confirmed by 2D NMR NOESY and single-crystal X-ray analysis suggesting that the endo-E-Syn transition state would be the most favored pathway of the reaction. Many heterocycles of this new series were found active against six bacterial and two fungal strains. In addition, all the compounds possess good anti-oxidant activity with the ferric reducing anti-oxidant power value >100mmol/100g. All new structures were docked into active site of angiotensin I converting enzyme (ACE), assuming that the compounds possessed the anti-hypertensive activity potential on the basis of prediction of activity spectra of substances prediction results. Pyranyl ring oxygen in compound 9a forms two hydrogen bonds with HIS353 and HIS513 residues in the active site of the ACE having good G score (- 4.06) of this compound, comparable to that of the reference drug captopril (- 4.93). Graphical Abstract: [Figure not available: see fulltext.]
An efficient synthesis of some thiopyranopyrazole-heterocycles via domino reaction in a Bronsted acidic ionic liquid
Parmar, Narsidas J.,Parmar, Bhagyashri D.,Sutariya, Tushar R.,Kant, Rajni,Gupta, Vivek K.
supporting information, p. 6060 - 6064 (2015/01/08)
The thiopyrazole gave many new polycyclic thiopyranopyrazole-heterocycles when it was assembled with a variety of O-alkenylated/alkynylated salicylaldehydes and naphthaldehydes in Bronsted acidic ionic liquid, [Hmim]HSO4, via domino/Knoevenagel-hetero-Diels-Alder (DKHDA) reaction. The reaction is highly stereoselective and the work-up procedure required no chromatography of products in many cases.
Microwave-assisted K-10 montmorillonite clay-mediated knoevenagel hetero-Diels-Alder reactions: A novel protocol for the synthesis of polycyclic pyrano[2,3,4-kl]xanthene derivatives
Ramesh, Ekambaram,Raghunathan, Raghavachary
experimental part, p. 613 - 625 (2009/07/04)
The intramolecular hetero-Diels-Alder reactions of 2-(cyclohex-2-enyloxy) benzaldehyde by Knoevenagel condensation with symmetrical 1,3-diones under three different conditions afforded the pyrano[2,3,4-kl]xanthene derivatives in a stereoselective manner i
A new domino-Knoevenagel-hetero-Diels-Alder reaction
Matiychuk, Vasyl S.,Lesyk, Roman B.,Obushak, Mykola D.,Gzella, Andrzej,Atamanyuk, Dmytro V.,Ostapiuk, Yuri V.,Kryshchyshyn, Anna P.
, p. 4648 - 4651 (2008/09/21)
Various novel 3,5a,6,11b-tetrahydro-2H,5H-chromeno[4′,3′:4,5]thiopyrano[2, 3-d][1,3]thiazol-2-ones were synthesized in 60-80% yields via domino-Knoevenagel-hetero-Diels-Alder reactions of 4-thioxo-1,3-thiazolidin-2-one with 3,7-dimethyl-6-octenal, 2-allyl
Hexahydrodibenzodioxane compounds and pharmaceutical compositions
-
, (2008/06/13)
The invention is dealing with antispasmodic compounds of the formula I STR1 in which R1 denotes H, halogen or a linear or branched C1 to C3 alkoxy or alkyl group, R2, R3 and R4 separately d
Stereoselective Formation of Polycyclic Systems by Intermolecular Cycloaddition of Carbonyl Ylides to Cyclic C=C-Bonds
Brokatzky-Geiger, Juergen,Eberbach, Wolfgang
, p. 2383 - 2389 (2007/10/02)
Intramolecular cycloadditions of carbonyl ylides 2, generated by thermolysis of the ene-oxiranes 1, are investigated with special regard to the stereochemical course of the reaction.On heating up to 180 deg C the expected transformations of 1a-d take plac
