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Annulation

About: Annulation is a research topic. Over the lifetime, 10152 publications have been published within this topic receiving 189701 citations.


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Journal ArticleDOI
TL;DR: The gold(III)-catalyzed sequential amination/annulation reaction of 2-propynyl-1,3-dicarbonyl compounds with primary amines produces 1,2,3,5-substituted pyrroles in moderate to high yields.
Abstract: The gold(III)-catalyzed sequential amination/annulation reaction of 2-propynyl-1,3-dicarbonyl compounds 1with primary amines 2produces 1,2,3,5-substituted pyrroles 4 in moderate to high yields.

99 citations

Journal ArticleDOI
TL;DR: Implementation of an enantioselective Michael addition followed by an intramolecular aldol reaction catalyzed by two phosphoric acids has enabled the synthesis of cyclohexenone derivatives with excellent enantiOSElectivities.
Abstract: Let's resolve our differences: Implementation of an enantioselective Michael addition followed by an intramolecular aldol reaction catalyzed by two phosphoric acids has enabled the synthesis of cyclohexenone derivatives with excellent enantioselectivities. Prominent kinetic resolution was observed in the latter reaction. Ar = aromatic group, X = H, halogen, Y = H, Me, halogen.

99 citations

Journal ArticleDOI
TL;DR: A new imide chiral auxiliary, endo-7-(2-benzoxazolyl)-1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-one (5), is from Kemp's triacid and resolved via its menthyl carbamate.
Abstract: A new imide chiral auxiliary, endo-7-(2-benzoxazolyl)-1,5,7-trimethyl-3-azabicyclo[3.3.1]nonan-2-one (5), is from Kemp's triacid and resolved via its menthyl carbamate. Mixed fumarate derivatives of the auxiliary show unprecedented control of regiochemistry and β-stereochemistry in representative radical addition reactions. Chiral radicals derived from 5 also show extremely high levels of stereoselectivity in representative radical allylation and cyclization reactions. Structural features of the chiral auxiliary and features of radical addition are integrated into a model for stereoselection

99 citations

Journal ArticleDOI
Yuanbin Zhang1, Yuji Sun1, Furong Lin1, Jiyong Liu1, Simon Duttwyler1 
TL;DR: 1,2,3-Trisubstituted closo-dodecaborates with B-O, B-N, and B-C bonds as well as a fused borane oxazole ring have been synthesized by rhodium-catalyzed direct cage B-H alkenylation and annulation of ureido boranes in the first reported example of regioselective B- H bond functionalization of the [B12
Abstract: 1,2,3-Trisubstituted closo-dodecaborates with B−O, B−N, and B−C bonds as well as a fused borane oxazole ring have been synthesized by rhodium-catalyzed direct cage B−H alkenylation and annulation of ureido boranes in the first reported example of regioselective B−H bond functionalization of the [B12H12]2− cage by transition-metal catalysis. This reaction proceeded at room temperature under ambient conditions and exhibited excellent selectivity for efficient monoalkenylation with good functional-group tolerance. The urea moiety enabled B−H activation by acting as a directing group, was incorporated in the oxazole ring in situ, and also avoided multiple alkenylation. A possible mechanism is proposed on the basis of the isolation of a rhodium agostic intermediate and control experiments.

99 citations

Journal ArticleDOI
Lei Peng1, Kai Li1, Chuandong Xie1, Shan Li1, Da Xu1, Wenling Qin1, Hailong Yan1 
TL;DR: A chiral Brønsted base-catalyzed asymmetric annulation of ortho-alkynylanilines has been developed to access axially chiral naphthyl-C2-indoles through vinylidene Ortho-quinone methides intermediates, providing a unique organocatalytic atroposelective route to axiallychiral aryl-C1-indole skeletons with excellent enantioselectivity and functional group tolerance.
Abstract: A chiral Bronsted base catalyzed asymmetric annulation of ortho-alkynylanilines has been developed to access axially chiral naphthyl-C2-indoles via vinylidene ortho-quinone methide (VQM) intermediates. This strategy provides a unique organocatalytic atroposelective route to axially chiral aryl-C2-indole skeletons with excellent enantioselectivity and functional-group tolerance. This transformation was applicable to decagram-scale preparation (50.0 g) with perfect enantioselectivity through simple recrystallization. Moreover, the utility of this reaction was demonstrated by a variety of transformations towards chiral naphthyl-C2-indoles for a series of carbon-heteroatom bond formations. Furthermore, the prepared axially chiral naphthyl-C2-indoles were applied as a chiral skeleton for organocatalytic aza-Baylis-Hillman reaction and asymmetric formal [4+2] tandem cyclization to give the corresponding adducts in high yields with improved enantioselectivity and diastereoselectivity.

99 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023468
2022850
2021754
2020618
2019699
2018603