Stereoselective Synthesis of Highly Substituted Cyclopentenones through [4+1] Annulations of Trialkylsilyl Vinyl Ketenes with α‐Benzotriazolyl Organolithium Compounds

Davie, Christopher P.; Danheiser, Rick

doi:10.1002/anie.200501579

Cited by 57 publications

(13 citation statements)

References 26 publications

(8 reference statements)

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“…Since there are a lot of experimental data regarding the organolithium reactions 27–34, 49–55, the present findings will surely be helpful in characterizing the possible reaction mechanisms in solutions with Li‐containing systems. More testing examples are still underway for further characterization.…”

Section: Resultsmentioning

confidence: 88%

Test and modification of the van der Waals' radii employed in the default PCM model

Chasse

Fang

2008

Int J of Quantum Chemistry

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ABSTRACT:High level ab initio calculations at the B3LYP/6-311ϩϩG(d,p) and MP2(full)/6-311ϩϩG(d,p) levels employing PCM/UA0 model with different van der Waals' radii for the systems that contain lithium atoms have been carried out, in order to see if the van der Waal's radius for lithium atom employed in the default PCM/UA0 model is proper or not. Comparative analysis indicated that the van der Waals' radius for alkali metals, especially for lithium atom in the default PCM/UA0 model within the Gaussian 03 package, is too small, which causes erroneous redundant imaginary frequencies (RIFs) in the characterization of Li-containing compounds from moderate to big size. A new set of van der Waals' atomic radii based on QTAIM, proposed by Bader, was suggested for a better choice in the characterization of compounds containing alkali metals, for which it can effectively avoid the erroneous RIFs for corresponding geometries of these Li-containing systems.

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Section: Resultsmentioning

confidence: 88%

Test and modification of the van der Waals' radii employed in the default PCM model

Chasse

Fang

2008

Int J of Quantum Chemistry

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“…The high reactivity of carbenes is, however, responsible for a low functional‐group tolerance. Alternatives to carbenes have thus been explored by using carbenoid reagents, such as isocyanides,5 carbon monoxide (and transition‐metal catalysis),6 ylides,7 α‐benzotriazolyl lithium compounds8 or palladium catalysis 9. Other four‐carbon units have also been considered, such as ω‐halogeno‐alkenes10 or 2‐(acetoxymethyl)‐buta‐2,3‐dienoate 11.…”

Section: Methodsmentioning

confidence: 99%

Formal Asymmetric (4+1) Annulation Reaction between Sulfur Ylides and 1,3‐Dienes

Rousseau

Delaunay

Dequirez

et al. 2015

Chemistry A European J

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A highly enantioselective synthesis of functionalized cyclopentanoids by a formal asymmetric (4+1) annulation strategy was developed. The methodology consists of a stereoselective cyclopropanation reaction between chiral sulfur ylides and 1,3-dienes followed by a, in situ, stereospecific MgI2 -catalyzed rearrangement of vinylcyclopropanes. This method is distinguished by a remarkable compatibility with functional groups and a high stereocontrol.

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“…If a[ 4 + +1] pathway proceeded, [18] the construction of af unctionalized cyclopentenone motif [19] under atypical metal-free conditions would be anticipated. [20] In this context, in view of producing synthetically useful cyclopentenonyl enamines and imines,w er eport herein original results on novel [4+ +1] annulations of allene 1 with methyl ketimines and enamines (two geminal C À Cb ond formations through ao ne-pot method). Indeed, the synthesis of these building blocks and their applications have drawn particular interest; [21] for example,p yracyclumines C, A, and D-isolated from the roots of Anacyclus pyrethrum feature this type of key substructure (Scheme 2c).…”

Section: Introductionmentioning

confidence: 99%

Phosphine‐Catalyzed [4+1] Cycloadditions of Allenes with Methyl Ketimines, Enamines, and a Primary Amine

et al. 2019

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Unprecedented phosphine-catalyzed [4+ +1] cycloadditions of allenyl imides have been discovered using various N-based substrates including methyl ketimines,e namines,a nd ap rimary amine.T hese transformations provideaone-pot access to cyclopentenoyl enamines and imines,o r( chiral) glactams through two geminal C À Cb ond or two C À Nb ond formations,r espectively.S everal P-based key intermediates including a1 ,4-(bis)electrophilic a,b-unsaturated ketenyl phosphonium species have been detected by 31 PNMR and HRMS analyses,w hich shed light on the postulated catalytic cycle.T he synthetic utility of this new chemistry has been demonstrated through ag ram-scaling up of the catalytic reaction as well as regioselective hydrogenation and double condensation to form cyclopentanoyl enamines and fused pyrazole building blocks,respectively. Scheme 1. Pioneering examples of allene-imine annulations through nucleophilic catalysis.

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Stereoselective Synthesis of Highly Substituted Cyclopentenones through [4+1] Annulations of Trialkylsilyl Vinyl Ketenes with α‐Benzotriazolyl Organolithium Compounds

Cited by 57 publications

References 26 publications

Test and modification of the van der Waals' radii employed in the default PCM model

Test and modification of the van der Waals' radii employed in the default PCM model

Formal Asymmetric (4+1) Annulation Reaction between Sulfur Ylides and 1,3‐Dienes

Phosphine‐Catalyzed [4+1] Cycloadditions of Allenes with Methyl Ketimines, Enamines, and a Primary Amine

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