Noncovalent Organocatalytic Synthesis of Enantioenriched Terminal Aziridines with a Quaternary Stereogenic Center
作者:Claudia De Fusco、Tiziana Fuoco、Gianluca Croce、Alessandra Lattanzi
DOI:10.1021/ol3017066
日期:2012.8.17
A high-yielding and enantioselective access to novel N-Boc terminal aziridines, bearing a quaternarystereogeniccenter, has been developed via an aza-Michael initiated ring-closure (aza-MIRC) reaction of α-acyl acrylates with an N-tosyloxy tert-butyl carbamate catalyzed by a chiral amino thiourea. The feasibility of the aziridine regioselective ring-opening to valuable α,α-disubstituted α-amino acid
Electron-Donor–Acceptor Complex-Enabled Flow Methodology for the Hydrotrifluoromethylation of Unsaturated β-Keto Esters
作者:Gabriel M. F. Batista、Pedro P. de Castro、Hélio F. Dos Santos、Kleber T. de Oliveira、Giovanni W. Amarante
DOI:10.1021/acs.orglett.0c03187
日期:2020.11.6
(EDA) complex-enabled flow photochemical hydrotrifluoromethylation of unsaturated β-keto esters is described. The developed protocol has an easy experimental procedure and does not require the use of transition-metal-based photocatalysts, allowing the isolation of 14 new compounds in up to 86% yield. Control experiments and computational studies revealed that the reaction proceeds through a Michael-type
Enantioselective Synthesis of 3,5,6‐Substituted Dihydropyranones and Dihydropyridinones using Isothiourea‐Mediated Catalysis
作者:Daniel G. Stark、Louis C. Morrill、David B. Cordes、Alexandra M. Z. Slawin、Timothy J. C. O'Riordan、Andrew D. Smith
DOI:10.1002/asia.201500907
日期:2016.2
isothiourea-catalyzed processes has been expanded and explored through the use of 2-N-tosyliminoacrylates and 2-aroylacrylates in a Michael addition-lactonization/lactamization cascade reaction. Notably, to ensure reproducibility it is essential to use homoanhydrides as ammonium enolate precursors with 2-aroyl acrylates, while carboxylic acids can be used with 2-N-tosyliminoacrylates, delivering a range of 3,5,6-substituted
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‐Dichlorocyclopropanation of Dicarbonyl Derivatives
作者:Gabriel M. F. Batista、Pedro P. De Castro、Arthur G. Carpanez、Bruno A. C. Horta、Giovanni W. Amarante
DOI:10.1002/chem.201904149
日期:2019.12.20
A novel methodology for the 1,1‐dichlorocyclopropanation of dicarbonyl conjugated olefins was described. The developed protocol is simple and uses readily accessible starting materials, allowing the isolation of the desired adducts in moderate to excellent yields (up to 99 %). Furthermore, the reaction tolerated scale up to the gram scale; thus highlighting the synthetic potential of this transformation
Diamine-mediated degradative dimerisation of Morita–Baylis–Hillman ketones
作者:Ajit Kumar Jha、Anju Kumari、Srinivasan Easwar
DOI:10.1039/c9cc10068g
日期:——
A degradative dimerisation of Morita-Baylis-Hillmanketones was observed in the presence of a primary diamine. The reaction proceeded swiftly to produce methylene-bridged 1,3-dicarbonyl compounds. A brief mechanisticinvestigation alluded to a retro-Mannich reaction as the key step of the transformation.