Results 41 to 50 of about 9,597,280 (150)

The intramolecular capture of thermally generated merocyanine dyes derived from naphthopyrans: Photochromism of 5-(diarylhydroxymethyl)-2H-naphtho[1,2-b]pyrans

, 2012
A series of 2H-naphtho[1,2-b]pyrans bearing a diarylmethanol unit at C-5 have been synthesised by the addition of an excess of an aryllithium reagent to alkyl 2H-naphtho[1,2-b]pyran-5-carboxylate precursors.
Kolla, Suresh B., Gibbons, Lucy V., Suresh B. Kolla, Christopher D. Gabbutt, Gabbutt, Christopher D., B. Mark Heron, Heron, B. Mark, Lucy V. Gibbons   +7 more
core   +1 more source

Ytterbium(III) Bis(Perfluorooctanesulfonyl)Imide Catalyzed One-Pot Synthesis of Tetrahydrobenzo[b]Pyrans in Fluorous Biphase System

, 2010
Ytterbium(III) bis(perfluorooctanesulfonyl)imide [Yb(NPf2)3] has been prepared, and used as an efficient catalyst for the synthesis of 4 H-benzo[ b]pyran derivatives by a one-pot three-component condensation of aldehydes, active methylene compounds, and
Chun Cai, Mei Hong
core   +1 more source

One Pot Synthesis of Spirocycles and Cyclopropa[b]pyrans by Alkenylation-Rearrangement of Cyclopropenes

, 2022
A one pot alkenylation followed by a stereoselective Alder-ene cycloisomerization of cyclopropenes give (aza)spiro[2.4]heptanes and spiro[2.5]octanes in high yields.
Eleonora Giona (13536112), Gema Domínguez (1651849), Alejandro Puet (9722329), Javier Pérez-Castells (1651846)   +3 more
core   +1 more source

One-pot, three-component, selective synthesis of the polyfunctionalized 4H-pyran and 4H-benzo[b]pyran derivatives in the presence of a highly efficient molecular sieve-supported zinc catalyst

, 2018
A series of pentasubstituted 4H-pyrans and tetrahydrobenzo[b]pyrans are synthesized with excellent yields via a one-pot condensation of aromatic aldehydes, malononitrile, and a dicarbonyl compound, ethyl acetoacetate, acetyl-acetone or dimedone, in the ...
Zoltán Hell, Ágnes Magyar
core   +1 more source

Control of the Fading Properties of Photochromic 3,3-Diaryl-3H-naphtho- [2,1-b]pyrans

, 2003
The synthesis and spectroscopic properties of some novel photochromic 3H-naphtho[2,1-b]pyrans are reported. Varying the size of an ortho-substituent on one of the geminal aryl rings allows the rate of fade of the photogenerated color to be ...
Gabbutt, Christopher D., Heron, B. Mark, Instone, Alicia C.   +2 more
core   +1 more source

Synthesis of new low-viscous sulfonic acid-functionalized ionic liquid and its application as a Brönsted liquid acid catalyst for the one-pot mechanosynthesis of 4H-pyrans through the ball milling process

, 2019
In the present study, a new low-viscous sulfonic acid-functionalized ionic liquid (SAIL) viz. 4,4′-trimethylene-N,N′-sulfonic acid-dipiperidinium chloride was synthesized and characterized by FTIR, 1D and 2D NMR, and Mass spectra.
Khaligh, Nader Ghaffari, Mihankhah, Taraneh, Johan, Mohd Rafie   +2 more
core   +1 more source

LaMnO₃ Supported Ionic Liquid; an Efficient Catalyst for One-Pot Three-Component Synthesis of Tetrahydrobenzo[b]Pyran Derivatives Under Solvent-Free Conditions

, 2019
A new recyclable nanocatalyst consisting of heteropoly acid grafted on ionic liquid modified LaMnO3 nanoparticles was synthesized and accomplished as an efficient catalyst in condensation reaction for the preparation of tetrahydrobenzo[b]pyrans under ...
Fahime Abbasinohoji (6692954), Hamid Reza Saadati-Moshtaghin (6692951)   +1 more
core   +1 more source

Pyrans and Their Benzo Derivatives:Synthesis

, 2020
Newly reported synthetic procedures to access pyrans and their benzo derivatives from 2007 to 2018 are summarized. The sub-chapters are organized by the structural similarity starting from pyrans, reduced, oxidized, and benzene-fused structures ...
Lauridsen, Jerik Mathew Valera, Lee, Ji-Woong, Kragh, Rasmus Refsgaard   +2 more
core   +1 more source

Gold(I)-catalysed one-pot synthesis of chromans using allylic alcohols and phenols [PDF]

, 2013
A gold(I)-catalysed reaction of allylic alcohols and phenols produces chromans regioselectively via a one-pot Friedel–Crafts allylation/intramolecular hydroalkoxylation sequence.
Barker, Graeme, Eloi Coutant, Lee, Ai-Lan, Coutant, Eloi, Paul C. Young, Ai-Lan Lee, Young, Paul C, Graeme Barker   +7 more
core   +1 more source

L-Pyrrolidine-2-Carboxylic Acid Sulfate: A New Ionic Liquid for the Synthesis of Bioactive Tetrahydrobenzo[b]pyrans

, 2017
Published ArticleMulticomponent reactions (MCRs), a significant subclass of reac tions, are one-pot processes in which three or four easily-approachable components react to form a single product.
Godse, Vaibhav W., Pawar, Parmeshwar P., Rindhe, Sahebrao S., Sonwane, Umesh R., Kendrekar, Pravin S., Pawar, Rajendra P.   +5 more
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