1,6-Aza-Michael addition of para-quinone methides with N-heterocycles catalyzed by Zn(OTf)2: A regioselective approach to N-diarylmethyl-substituted heterocycles
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DOI: 10.1016/j.tet.2020.131338
Abstract: Abstract An efficient Zn(OTf)2-catalyzed regioselective C–N bond making reaction between a bunch of aryl/heteroaryl-substituted para-quinone methides as ideal 1,6-acceptors and various aromatic/non-aromatic aza-heterocycles bearing N–H moiety namely carbazoles, pyrazoles, indazole, benzotriazole and saccharin is reported.… read more here.
Keywords: quinone methides; michael addition; para quinone; diarylmethyl substituted ... See more keywords
1,6-Conjugate sulfonylation of para-quinone methides: An expedient approach to unsymmetrical gem-diarylmethyl sulfones
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DOI: 10.1016/j.tetlet.2018.12.023
Abstract: Abstract A novel sulfonylation of para -quinone methides with sodium arylsulfinates has been developed via acetic acid promoted sulfa-Michael addition. This reaction provides an inexpensive and efficient method to synthesize various unsymmetrical diarylmethyl sulfones, displaying… read more here.
Keywords: sulfonylation para; para quinone; quinone methides; diarylmethyl sulfones ... See more keywords
Stereoselective synthesis of para-quinone monoketals through tri-bromide (TBr) mediated oxidative dearomatization of phenols
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DOI: 10.1016/j.tetlet.2020.151646
Abstract: Abstract A metal free one-pot stereoselective synthesis of para-quinone monoketals and their derivatives has been reported in this present work. Tri-bromides (TBrs) have been employed as an effective reagent for intramolecular spirocyclizations leading to excellent… read more here.
Keywords: synthesis para; quinone monoketals; stereoselective synthesis; para quinone ... See more keywords
Enantioselective 1,6-Addition of β-Ketoester Enolates to In Situ Generated para-Quinone Methides Enabled by Cooperative Palladium and Brønsted Acid Catalysis.
Sign Up to like & getrecommendations! Published in 2023 at "Organic letters"
DOI: 10.1021/acs.orglett.2c04127
Abstract: We report herein an asymmetric cooperative process for the enantioselective 1,6-addition of β-ketoesters to in situ generated para-quinone methides with chiral Pd-aqua complexes as mixed Brønsted acid-base catalysts. Excellent yields, outstanding enantiocontrol, and good diastereoselectivity… read more here.
Keywords: situ generated; generated para; para quinone; quinone methides ... See more keywords
Bismuth(III)-Catalyzed 1,8-Addition/Cyclization/Rearrangement of Propargylic para-Quinone Methides with 2-Vinylphenol: Synthesis of Indeno[2,1-c]chromenes.
Sign Up to like & getrecommendations! Published in 2023 at "Organic letters"
DOI: 10.1021/acs.orglett.3c00179
Abstract: The unique reactivity of in situ generated propargylic para-quinone methides as a new type of five-carbon synthon has been discovered by a novel bismuth(III)-catalyzed tandem annulation reaction. This 1,8-addition/cyclization/rearrangement cyclization cascade reaction is characterized by… read more here.
Keywords: para quinone; quinone methides; cyclization; bismuth iii ... See more keywords
Cascade Radical 1,6-Addition/Cyclization of para-Quinone Methides: Leading to Spiro[4.5]deca-6,9-dien-8-ones.
Sign Up to like & getrecommendations! Published in 2018 at "Organic letters"
DOI: 10.1021/acs.orglett.8b00518
Abstract: A cascade three-component iodoazidation of para-quinone methides to construct spiro[4.5]deca-6,9-dien-8-ones under mild conditions has been developed. The chemoselective 1,6-addition of azide radical triggered a regioselective 5-exo-dig cyclization/radical coupling sequence, enabling C-N, C-C, and C-I bond… read more here.
Keywords: spiro deca; quinone methides; dien ones; para quinone ... See more keywords
Visible-Light-Triggered Cyanoalkylation of para-Quinone Methides and Its Application to the Synthesis of GPR40 Agonists.
Sign Up to like & getrecommendations! Published in 2019 at "Organic letters"
DOI: 10.1021/acs.orglett.9b01325
Abstract: Cyanoalkylated diarylmethanes with biological and pharmacological potentials were synthesized from para-quinone methides and cyanoalkylating reagents through a photocatalytic process. This protocol is operationally simple and mild and has high efficiency, which gave the corresponding products… read more here.
Keywords: gpr40 agonists; synthesis gpr40; para quinone; quinone methides ... See more keywords
Recent developments in 1,6-addition reactions of para-quinone methides (p-QMs)
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DOI: 10.1039/d0qo00387e
Abstract: In recent years, para-quinone methides (p-QMs) have emerged as attractive and versatile synthons in organic synthesis owing to their high reactivity. Consequently, p-QM chemistry has attracted increasing attention and remarkable advances have been achieved. Among… read more here.
Keywords: addition; quinone methides; methides qms; chemistry ... See more keywords
Enantioselective synthesis of triarylmethanes via organocatalytic transfer hydrogenation of para-quinone methides.
Sign Up to like & getrecommendations! Published in 2022 at "Chemical communications"
DOI: 10.1039/d2cc01996e
Abstract: A new organocatalytic asymmetric method for the synthesis of enantioenriched triarylmethanes is developed. Different from the conventional approaches featuring asymmetric arylation, the present study employs asymmetric reduction via C-H bond formation as the key step.… read more here.
Keywords: enantioselective synthesis; quinone methides; synthesis triarylmethanes; para quinone ... See more keywords
Regioselective allenylation and propargylation of various para-quinone methides using alkynyl azaarenes as pronucleophiles.
Sign Up to like & getrecommendations! Published in 2022 at "Chemical communications"
DOI: 10.1039/d2cc03439e
Abstract: We have developed Brønsted base-mediated regioselective allenylation and propargylation of various para-quinone methides using unfunctionalized 2-alkynyl azaarenes as pronucleophiles. The appropriate choice of a base provides an opportunity to achieve either an allenylated product or… read more here.
Keywords: regioselective allenylation; para quinone; propargylation various; quinone methides ... See more keywords
Base-Promoted 1,6-Aza-Michael Addition of Azauracils to para-Quinone Methides
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DOI: 10.1055/a-2104-5943
Abstract: Here, we report an efficient higher order conjugate addition of azauracils to substituted para-Quinone methides (p-QMs) mediated by triethylamine to furnish hitherto unknown diarylmethane scaffolds through construction of a C-N bond. The protocol features mild… read more here.
Keywords: base promoted; addition azauracils; para quinone; promoted aza ... See more keywords