Palladium-Catalyzed Enantioselective Allylic Alkylations through C-H Activation
作者:Barry M. Trost、David A. Thaisrivongs、Etienne J. Donckele
DOI:10.1002/anie.201207870
日期:2013.1.28
reaction with 2‐acetyl‐1‐tetralones to form quaternary carbon stereocenters. This is a conceptually and mechanistically distinct strategy from traditional methods for the synthesis of enantioenriched allylic substitution products. 2,6‐DMBQ=2,6‐dimethylbenzoquinone.
An Experimental and in Situ IR Spectroscopic Study of the Lithiation–Substitution of <i>N</i>-Boc-2-phenylpyrrolidine and -piperidine: Controlling the Formation of Quaternary Stereocenters
作者:Nadeem S. Sheikh、Daniele Leonori、Graeme Barker、James D. Firth、Kevin R. Campos、Anthony J. H. M. Meijer、Peter O’Brien、Iain Coldham
DOI:10.1021/ja211398b
日期:2012.3.21
enantioselective synthesis of 2-substituted 2-phenylpyrrolidines and -piperidines, an important class of pharmaceutically relevant compounds that contain a quaternary stereocenter, has been developed. The approach involves lithiation-substitution of enantioenriched N-Boc-2-phenylpyrrolidine or -piperidine (prepared by asymmetric Negishi arylation or catalytic asymmetric reduction, respectively). The combined use
Probing the Stereoselectivity of the Heck Arylation of Endocyclic Enecarbamates with Diazonium Salts. Concise Syntheses of (2<i>S</i>,5<i>R</i>)-Phenylproline Methyl Ester and Schramm's C-Azanucleoside
作者:Elias A. Severino、Edson R. Costenaro、Ariel L. L. Garcia、Carlos Roque D. Correia
DOI:10.1021/ol027268a
日期:2003.2.1
[GRAPHICS]The diastereoselectivity of the Heck arylation of several chiral, nonracemic, five-membered endocyclic enecarbamates with aryldiazonium tetrafluoroborates was evaluated. The cis selectivity observed for some enecarbamates bearing coordinating groups was explored in the concise synthesis of the (2S,5R)-(+)-phenylproline methyl ester, a scaffold for the nonpeptide cholecystokinin antagonist (+)-RP 66803, and in the synthesis of Schramm's potent antiprotozoan C-azanucleoside.
A New Class of Non-<i>C</i><sub>2</sub>-Symmetric Ligands for Oxidative and Redox-Neutral Palladium-Catalyzed Asymmetric Allylic Alkylations of 1,3-Diketones
作者:Barry M. Trost、Etienne J. Donckele、David A. Thaisrivongs、Maksim Osipov、James T. Masters
DOI:10.1021/jacs.5b00786
日期:2015.2.25
We report the discovery, synthesis, and application of a new class of non-C-2-symmetric phosphoramidite ligands derived from pyroglutamic acid for use in both oxidative and redox-neutral palladium-catalyzed asymmetric allylic alkylations of 1,3-diketones. The resulting chiral products are typically obtained in high yield with good to excellent levels of enantioselectivity.
Enantiospecific synthesis and absolute configuration of (+)-RP 66803 a new non-peptide CCK antagonist
作者:Franco Manfré、Jean Pierre Pulicani
DOI:10.1016/s0957-4166(00)86178-9
日期:1994.1
Pyrrolidine derivatives have been identified as a new class of non-peptide CCK antagonists. Enantiomers of RP 66803, a representative compound of this chemical family were previously prepared by chiral chromatography of the racemate. In order to determine the absolute configuration of each one, we report herein an enantiospecificsynthesis leading to the (+)-isomer using anodic methoxylation as key