The first enantioselective aldehyde α-benzylation using electron-deficient aryl and heteroaryl substrates has been accomplished. The productive merger of a chiral imidazolidinone organocatalyst and a commercially available iridium photoredox catalyst in the presence of household fluorescent light directly affords the desired homobenzylic stereogenicity in good to excellent yield and enantioselectivity. The utility of this methodology has been demonstrated via rapid access to an enantioenriched drug target for angiogenesis suppression.
Download full-text PDF |
Source |
---|---|
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3056320 | PMC |
http://dx.doi.org/10.1021/ja106593m | DOI Listing |
Org Biomol Chem
January 2025
Chongqing Research Center for Pharmaceutical Engineering, College of Pharmacy, Chongqing Medical University, Chongqing 400016, China.
A novel palladium-catalyzed allylic C-H alkylation of terminal olefins with 3-carboxamide oxindoles is described. A variety of new 3-carboxamide-3-allylation oxindoles with an all-carbon quaternary center were obtained in moderate to good yields (up to 99%). In addition, the asymmetric version of this reaction was also explored, providing moderate enantioselectivity.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Department of Chemistry, The Scripps Research Institute, 10550 N. Torrey Pines Road, La Jolla, California 92037, United States.
The development of catalytic methods for the synthesis of enantiopure saturated heterocycles has been a long-standing challenge in asymmetric catalysis. We describe the first highly enantioselective palladium-catalyzed βC(sp)-H arylation and olefination of lactams for the preparation of various chiral N-heterocycles bearing quaternary carbon centers. The presence of strongly electron-withdrawing groups on the chiral bifunctional MPAThio ligand is crucial to the reactivity of weakly coordinating lactams.
View Article and Find Full Text PDFJ Am Chem Soc
January 2025
Institute of Organic Chemistry, University of Leipzig, 04103 Leipzig, Germany.
The enantioselective synthesis of 1,4-dicarbonyl compounds continues to pose a significant challenge in organic synthesis, and a catalytic process which generates two adjacent stereogenic centers with full stereochemical control is lacking until now. The 1,4-relationship of the functional groups requires an Umpolung strategy as one of the α-carbonyl positions has to be inverted into an electrophilic center to react with a normal enolate. We report herein the highly enantio- and diastereoselective addition of silyl ketene acetals toward electrophilic 1-azaallyl cations to furnish chiral 4-hydrazonoesters, which are masked 1,4-dicarbonyl compounds.
View Article and Find Full Text PDFBiotechnol Notes
December 2024
Centre for Molecular Biology, Central University of Jammu, Rahya Suchani (Bagla), Jammu & Kashmir, India.
The amidases (EC 3.5.1.
View Article and Find Full Text PDFAnal Chem
January 2025
School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure -1,2-diaminocyclohexane (-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in H NMR analysis. The highly efficient chiral recognition of CSA on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via H, F, and P NMR spectroscopy.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!