Catalytic Asymmetric Synthesis of Chiral Dihydrobenzofurans through a Formal [4+1] Annulation Reaction of Sulfur Ylides and In Situ Generated ortho‐Quinone Methides
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DOI: 10.1002/ejoc.201601186
Abstract: The first example of a catalytic asymmetric formal [4+1] annulation reaction between sulfur ylides and in situ generated ortho-quinone methides (o-QMs) is reported in this work. A C2-symmetric chiral urea was identified to be the… read more here.
Keywords: sulfur ylides; reaction sulfur; formal annulation; catalytic asymmetric ... See more keywords
Theoretical study of the [3 + 4] annulation reaction of 2-bromoenals with malonates catalyzed by N-heterocyclic carbene
Sign Up to like & getrecommendations! Published in 2021 at "Molecular Catalysis"
DOI: 10.1016/j.mcat.2021.111647
Abstract: Abstract A systematic density functional theory (DFT) computation has been performed to understand the mechanism and stereoselectivity involved in the [3 + 4] annulation reaction between 2-bromoenal and 3-formylindol-2-methyl-malonate catalyzed by N-heterocyclic carbene (NHC). The optimal reaction… read more here.
Keywords: annulation reaction; reaction; heterocyclic carbene; catalyzed heterocyclic ... See more keywords
Selective construction of indeno[1,2-b]phenothiazine and indeno[2,1-c]phenothiazine via tandem annulation reaction
Sign Up to like & getrecommendations! Published in 2018 at "Tetrahedron"
DOI: 10.1016/j.tet.2018.04.062
Abstract: Abstract AcOH promoted annulation reaction of 2-arylideneindane-1,3-diones with methyl 2-(benzo[b][1,4]thiazin-3-ylidene)acetate in refluxing ethanol afforded pentacyclic tetrahydroindeno [1,2-b]phenothiazine in satisfactory yields and with high diastereoselectivity according to the unexpected tandem annulation process. When the above reaction… read more here.
Keywords: phenothiazine; indeno phenothiazine; annulation reaction; tandem annulation ... See more keywords
Metal-Free-Catalyzed Three-Component [2+2+2] Annulation Reaction of [60]Fullerene, Ketones, and Indoles: Access to Diverse [60]Fullerene-Fused 1,2-Tetrahydrocarbazoles.
Sign Up to like & getrecommendations! Published in 2021 at "Organic letters"
DOI: 10.1021/acs.orglett.1c00195
Abstract: The first example of metal-free-catalyzed multicomponent annulation reaction of [60]fullerene has been developed for concise and efficient construction of novel [60]fullerene-fused 1,2-tetrahydrocarbazoles. Using inexpensive and readily available I2 as a catalyst, [60]fullerene, ketones, and indoles… read more here.
Keywords: annulation; free catalyzed; fullerene; metal free ... See more keywords
An Organic Intermolecular Dehydrogenative Annulation Reaction.
Sign Up to like & getrecommendations! Published in 2017 at "Organic letters"
DOI: 10.1021/acs.orglett.7b00562
Abstract: The discovery of a direct method for the synthesis of three-ring heterocyclic carbazoles from unactivated arenes and anilides by a metal-free (organic) intermolecular dehydrogenative annulation reaction under ambient laboratory conditions is reported. Iodine(III) was used… read more here.
Keywords: dehydrogenative annulation; organic intermolecular; annulation reaction; intermolecular dehydrogenative ... See more keywords
Domino Palladium-Catalyzed Double Norbornene Insertion/Annulation Reaction: Expeditious Synthesis of Overcrowded Tetrasubstituted Olefins.
Sign Up to like & getrecommendations! Published in 2019 at "Organic letters"
DOI: 10.1021/acs.orglett.9b01543
Abstract: A Pd-catalyzed domino process involving a double norbornene insertion/annulation reaction was developed for the expeditious synthesis of overcrowded olefins. In this one-pot reaction, four new C-C bond formations were achieved by three consecutive Heck carbopalladations… read more here.
Keywords: expeditious synthesis; double norbornene; norbornene insertion; reaction ... See more keywords
Palladium(ii)-catalyzed vinylic geminal double C-H activation and alkyne annulation reaction: synthesis of pentafulvenes.
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DOI: 10.1039/c9cc09564k
Abstract: The first transition-metal-catalyzed vinylic geminal double C(sp2)-H activation and di-substituted alkyne annulation reaction is reported. This palladium(ii)-catalyzed, amide directed reaction of vinylic compounds with di-substituted alkynes offers an efficient synthetic path to pentafulvenes, which are… read more here.
Keywords: geminal double; reaction; catalyzed vinylic; alkyne annulation ... See more keywords
Synthesis of 4-ethenyl quinazolines via rhodium(iii)-catalyzed [5 + 1] annulation reaction of N-arylamidines with cyclopropenones
Sign Up to like & getrecommendations! Published in 2020 at "Organic chemistry frontiers"
DOI: 10.1039/c9qo01372e
Abstract: An unprecedented synthesis of 4-ethenyl quinazolines via a Rh(III)-catalyzed C–H activation and annulation reaction was described. In particular, when C-alkyl imidamides are benzyl groups, 2-benzoyl quinazolines can be obtained. This protocol enables the effective application… read more here.
Keywords: ethenyl quinazolines; iii catalyzed; reaction; synthesis ethenyl ... See more keywords
Synthesis of spiro(indoline-2,3′-hydropyridazine) via an “on-water” [4 + 2] annulation reaction
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DOI: 10.1039/d0qo01422b
Abstract: An on-water [4 + 2] annulation reaction between 2-methyl-3H-indolium salt and α-bromo N-acyl hydrazone has been developed. The environmentally friendly strategy provides the first facile access to spiro(indoline-2,3'-hydropyridazine) scaffolds. read more here.
Keywords: indoline hydropyridazine; annulation reaction; water annulation; spiro indoline ... See more keywords
Cascade annulation reaction (CAR): highly diastereoselective synthesis of pyranopyrazole scaffolds
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DOI: 10.1039/d0ra03400b
Abstract: An unprecedented domino protocol for the novel synthesis of highly diverse and functionalized tetrahydro pyranopyrazole scaffolds using chalcone epoxide has been reported for the first time. This synthetic protocol generates three consecutive stereogenic centres in… read more here.
Keywords: pyranopyrazole scaffolds; synthesis; highly diastereoselective; cascade annulation ... See more keywords
Sc(OTf)3 catalyzed [3 + 2]-annulation reaction of donor–acceptor aziridines with methylene exo-glycals: synthesis of chiral carbohydrate-spiro-heterocycles
Sign Up to like & getrecommendations! Published in 2021 at "Organic chemistry frontiers"
DOI: 10.1039/d1qo00228g
Abstract: A Sc(OTf)3 catalyzed [3 + 2]-annulation reaction between donor–acceptor aziridines and several exo-glycals has been developed. Using this method, some exo-glycals derived from D-ribose, D-galactose and uridine can be converted into carbohydrate-spiro-heterocycles easily in good… read more here.
Keywords: annulation reaction; catalyzed annulation; reaction; reaction donor ... See more keywords