Catalytic Asymmetric Synthesis of Chiral Dihydrobenzofurans through a Formal [4+1] Annulation Reaction of Sulfur Ylides and In Situ Generated ortho‐Quinone Methides
Sign Up to like & getrecommendations! Published in 2017 at "European Journal of Organic Chemistry"
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
Base-promoted formal [4 + 1+1] annulation of aldehyde, N-benzyl amidine and DMSO toward 2,4,6-triaryl pyrimidines
Sign Up to like & getrecommendations! Published in 2017 at "Tetrahedron Letters"
DOI: 10.1016/j.tetlet.2017.11.020
Abstract: Abstract A base-promoted formal [4 + 1+1] annulation of aldehyde, N-benzyl amidine and DMSO was developed, leading to a series of 2,4,6-triaryl pyrimidines in moderate to good yields. Notably, DMSO served as a methine source, which was… read more here.
Keywords: aldehyde benzyl; promoted formal; formal annulation; benzyl amidine ... See more keywords
N-Heterocyclic Carbene-Catalyzed Enantioselective Synthesis of Carbocycle-Fused Uracils via Formal [4 + 2] Annulation/Lactone Formation/Decarboxylation Cascade.
Sign Up to like & getrecommendations! Published in 2022 at "Organic letters"
DOI: 10.1021/acs.orglett.2c01165
Abstract: An unprecedented organocatalytic asymmetric construction of novel six-membered carbocycle fused uracils has been demonstrated by the reaction of the remotely enolizable 6-methyluracil-5-carbaldehydes with 2-bromoenals. The reaction involves an N-heterocyclic carbene-catalyzed formal [4 + 2] annulation… read more here.
Keywords: fused uracils; formal annulation; carbene catalyzed; carbocycle fused ... See more keywords
Enantioselective Synthesis of Functionalized Tetrahydropyridines through Iridium-Catalyzed Formal [5+1] Annulation.
Sign Up to like & getrecommendations! Published in 2022 at "Organic letters"
DOI: 10.1021/acs.orglett.2c02750
Abstract: An efficient iridium-catalyzed asymmetric formal [5+1] annulation by in situ generation of enamines as N-nucleophiles for the synthesis of tetrahydropyridine derivatives is disclosed. The methodology offers direct access to a wide variety of chiral tetrahydropyridine… read more here.
Keywords: formal annulation; iridium catalyzed; synthesis functionalized; enantioselective synthesis ... See more keywords
Formal [3 + 4] Annulation of α,β-Unsaturated Acyl Azoliums: Access to Enantioenriched N-H-Free 1,5-Benzothiazepines.
Sign Up to like & getrecommendations! Published in 2017 at "Organic letters"
DOI: 10.1021/acs.orglett.7b01457
Abstract: An unprecedented formal [3 + 4] annulation of α,β-unsaturated acyl azoliums with 2-aminobenzenethiols has been utilized to synthesize enantioenriched N-H-free 1,5-benzothiazepines, which are recognized as privileged structures in numerous biologically active scaffolds. This protocol offers… read more here.
Keywords: acyl azoliums; unsaturated acyl; enantioenriched free; formal annulation ... See more keywords
Formal [5+1] annulation reactions of dielectrophilic peroxides: facile access to functionalized dihydropyrans.
Sign Up to like & getrecommendations! Published in 2020 at "Chemical communications"
DOI: 10.1039/d0cc05565d
Abstract: A general [5+1] annulation reaction, which utilized 4-bromo- or 4-mesyloxy-but-2-enyl peroxides as unique five-atom bielectrophilic synthons to participate in the C-C and the subsequent umpolung C-O bond-forming reactions with C1 nucleophiles, has been developed for… read more here.
Keywords: annulation; annulation reactions; dielectrophilic peroxides; formal annulation ... See more keywords
Tandem Oxidative Phenol Dearomatization/Formal [3+2] Annulation Protocol En Route to Highly Functionalized Benzothiophenes
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DOI: 10.1055/s-0036-1588415
Abstract: A new strategy for the synthesis of benzothiophenes through formal [3+2] annulation of sulfanylacetaldehyde and cyclohexa-2,4-dien-1-one monoketals has been developed. This approach relies on the ease of aromatization of tetrahydrobenzothiophenone derivatives prepared by the aforementioned… read more here.
Keywords: tandem oxidative; annulation; oxidative phenol; formal annulation ... See more keywords