Synthesis of α,β-Unsaturated Ketones by Pd-Catalyzed Decarboxylative Allylation of α-Oxocarboxylates
作者:Nuria Rodríguez、Filipe Manjolinho、Matthias F. Grünberg、Lukas J. Gooßen
DOI:10.1002/chem.201102584
日期:2011.12.2
A palladium/p‐tolylphosphine system has been developed that catalyzes the extrusion of carbon dioxide from α‐oxocarboxylic acid allyl esters, leading to α,β‐unsaturated ketones (see scheme). The palladium complex activates the substrate and mediates the carbon–carbon bond formation to give allyl ketones, and subsequent double bond shift to the α,β position. The actual decarboxylation step with formation
Synthesis of γ,δ-unsaturated quaternary α-alkylamino acids using umpolung reaction and Claisen rearrangement
作者:Isao Mizota、Katsuki Tanaka、Makoto Shimizu
DOI:10.1016/j.tetlet.2012.01.133
日期:2012.4
A new synthesis of γ,δ-unsaturated quaternary α-amino acid derivatives was developed utilizing N-alkylation and Claisen rearrangement of allyl α-iminocarboxylates.
An investigation of structure-reactivity relationships of δ-alkenyl oximes; competitive thermal reactions leading to cyclic nitrones and/or N-unsubstituted bicyclic isoxazolidines
作者:Linda Doyle、Frances Heaney
DOI:10.1016/j.tet.2010.06.005
日期:2010.8
Thermal reactions of C-aryl δ-alkenyl oximes give N-unsubstituted bicylic lactone, lactam and pyrrolidine fusedisoxazolidines by an intramolecular oxime olefin cycloaddition pathway (IOOC) and/or cyclic nitrones by an azaprotio cyclotransfer (APT) route; a number of factors, including the nature of the aryl group, the oxime geometry and the structure of the linker between the oxime and the terminal
Copper-catalyzed Pummerer type reaction of α -thio aryl/heteroarylacetates: Synthesis of aryl/heteroaryl α -keto esters
作者:Pipas Saha、Sumit Kumar Ray、Vinod K. Singh
DOI:10.1016/j.tetlet.2017.03.069
日期:2017.5
A copper catalyzed Pummerer type reaction of α-thio aryl/heteroarylacetates is described for the first time. This transformation represents a new route to synthesize α-keto esters, which are important intermediates for pharmaceuticals and organic synthesis. The reaction proceeds via in situ generation of a thionium ion that undergoes hydrolysis to furnish α-keto esters in synthetically viable yields
X=Y-ZH systems as potential 1,3-dipoles. Part 33. Generation of nitrones from oximes. Tandem Michael addition-1,3-dipolar cycloaddition reactions. Class 2 processes in which the dipolarophile is located within the oxime.
corresponding C-alkenyl nitrones which undergo an intramolecular cycloaddition. The cycloaddition can occur by one of two modes leading to either bridged- or fused-isoxazolidines. The latter is preferred in most cases except that of the C-(3-alkenyl) nitrone which gives exclusively the bridged-ring product and the C-(4-alkenyl)nitrones derived from N-allylpyrrole-2-carboxyaldehyde oxime which gives both bridged-