We report a highly enantioselective, general catalytic system for the facile synthesis of tertiary stereocenters by protonation adjacent to cyclic ketones. The method relies on catalytic decarboxylative protonation of readily accessible racemic quaternary beta-ketoesters. A range of substituted cycloalkanone compounds can be accessed through this process with high levels of enantioselectivity.
作者:Douglas C. Behenna、Justin T. Mohr、Nathaniel H. Sherden、Smaranda C. Marinescu、Andrew M. Harned、Kousuke Tani、Masaki Seto、Sandy Ma、Zoltán Novák、Michael R. Krout、Ryan M. McFadden、Jennifer L. Roizen、John A. Enquist、David E. White、Samantha R. Levine、Krastina V. Petrova、Akihiko Iwashita、Scott C. Virgil、Brian M. Stoltz
DOI:10.1002/chem.201003383
日期:2011.12.9
functions with nearly identical efficiency in terms of yield and enantioselectivity. Catalyst discovery and development, the optimization of reaction conditions, the exploration of reactionscope, and applications in target‐directed synthesis are reported. Experimental observations suggest that these alkylationreactions occur through an unusual inner‐sphere mechanism involving binding of the prochiral
The Inner-Sphere Process in the Enantioselective Tsuji Allylation Reaction with (<i>S</i>)-<i>t</i>-Bu-phosphinooxazoline Ligands
作者:John A. Keith、Douglas C. Behenna、Justin T. Mohr、Sandy Ma、Smaranda C. Marinescu、Jonas Oxgaard、Brian M. Stoltz、William A. Goddard
DOI:10.1021/ja070516j
日期:2007.10.1
We propose an inner-sphere mechanism explaining the unique performance of the Tsuji asymmetrical allylation reaction using hard prochiral enolate nucleophiles and non-prochiral allyl groups. Using first principles quantum mechanics (B3LYP density functional theory), we find that the pathway for this reaction involves nucleophilic attack followed by interconversion from a five-coordinate Pd complex
Enantioselective, catalytic allylation of ketones and olefins
申请人:Behenna C. Douglas
公开号:US20060084820A1
公开(公告)日:2006-04-20
Compounds containing a substituted or unsubstituted allyl group directly bound to a chiral carbon atom are prepared enantioselectively. Starting reactants are either chiral or achiral, and may or may not contain an attached allyloxycarbonyl group as a substituent. Chiral ligands are employed, along with transition metal catalysts. The methods of the invention are effective in providing enantioconvergent allylation of chiral molecules.
A palladium-catalysed enolate alkylation cascade for the formation of adjacent quaternary and tertiary stereocentres
作者:Jan Streuff、David E. White、Scott C. Virgil、Brian M. Stoltz
DOI:10.1038/nchem.518
日期:2010.3
problems simultaneously and allows the installation of vicinal all-carbon quaternary and tertiary stereocentres at the α-carbon of a ketone in a single step. This multiple bond-forming process is carried out on readily available β-ketoester starting materials and proceeds by conjugate addition of a palladium enolate, generated in situ, to activated Michael acceptors. As a result, the CO2 moiety of the
Palladium‐Based Dyotropic Rearrangement Enables A Triple Functionalization of <i>Gem</i>‐Disubstituted Alkenes: An Unusual Fluorolactonization Reaction
作者:Qiang Feng、Chen‐Xu Liu、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202316393
日期:2024.1.2
4-methylenealkanoic acid derivatives with Selectfluor provides fluorolactones via a sequence of 5-exo-trig oxypalladation, Pd oxidation, regioselective ring-enlarging 1,2-alkyl/Pd(IV) dyotropic rearrangement and C−F bond-forming reductive elimination.