Asymmetric Hydroformylation of <i>Z</i>-Enamides and Enol Esters with Rhodium-Bisdiazaphos Catalysts
作者:M. Leigh Abrams、Floriana Foarta、Clark R. Landis
DOI:10.1021/ja507701k
日期:2014.10.15
Asymmetric hydroformylation (AHF) of Z-enamides and Z-enol esters provides chiral, alpha-functionalized aldehydes with high selectivity and atom economy. Rh-bisdiazaphospholane catalysts enable hydroformylation of these challenging disubstituted substrates under mild reaction conditions and low catalyst loadings. The synthesis of a protected analog of l-DOPA demonstrates the utility of AHF for enantioselective
anti-Markovnikov addition of primary amides to terminalalkynes under the formation of Z-configured secondaryenamides is efficiently promoted by a catalyst system generated in situ from bis(2-methallyl)(cycloocta-1,5-diene)ruthenium(II), 1,4-bis(dicyclohexylphosphino)butane, and ytterbium triflate. The thermodynamically more stable E-isomers are accessible by combining the above hydroamidation with an in
construction of a rich chemical space of arylethylamine motif. In this report, a practical protocol for the synthesis of arylethylamine functionality common in pharmaceutical chemicals has been developed. It proceeds by Mn-catalyzed anti-Markovnikov hydroarylation of electron-rich enamides under mild conditions without the use of ligands. In spite of mismatched electronic effects during the manganese-mediated
Synthesis of Secondary Enamides by Ruthenium-Catalyzed Selective Addition of Amides to Terminal Alkynes
作者:Lukas J. Gooßen、Kifah S. M. Salih、Mathieu Blanchot
DOI:10.1002/anie.200803068
日期:2008.10.20
A Doubly Axially Chiral Phosphoric Acid Catalyst for the Asymmetric Tandem Oxyfluorination of Enamides
作者:Takashi Honjo、Robert J. Phipps、Vivek Rauniyar、F. Dean Toste
DOI:10.1002/anie.201205383
日期:2012.9.17
Double agent: Enantioselective tandemoxyfluorination of enamides using a doublyaxiallychiralphosphoricacidcatalyst is reported. The chiralphosphoricacidcatalyst controls both a fluorination step, using a chiral anion phase‐transfer strategy, and addition to the resulting imine under the guise of Brønsted acid catalysis.