Palladium(II)-Catalyzed Enantioselective C(sp3)–H Activation Using a Chiral Hydroxamic Acid Ligand
نویسندگان
چکیده
An enantioselective method for Pd(II)-catalyzed cross-coupling of methylene β-C(sp(3))-H bonds in cyclobutanecarboxylic acid derivatives with arylboron reagents is described. High yields and enantioselectivities were achieved through the development of chiral mono-N-protected α-amino-O-methylhydroxamic acid (MPAHA) ligands, which form a chiral complex with the Pd(II) center. This reaction provides an alternative approach to the enantioselective synthesis of cyclobutanecarboxylates containing α-chiral quaternary stereocenters. This new class of chiral catalysts also show promises for enantioselective β-C(sp(3))-H activation of acyclic amides.
منابع مشابه
Palladium(0)-catalyzed asymmetric C(sp3)–H arylation using a chiral binol-derived phosphate and an achiral ligand† †Electronic supplementary information (ESI) available: Full optimization tables, procedural, spectral and X-ray crystallographic (CIF) data, and DFT calculations. CCDC 1486752 and 1486753. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c6sc04006c Click here for additional data file. Click here for additional data file.
The first efficient palladium(0)-catalyzed enantioselective C(sp)–H activation reaction using a catalytic chiral base and an achiral phosphine ligand is reported. Fine-tuning the binol-derived phosphoric acid pre-catalyst and the reaction conditions was found to be crucial to achieve high levels of enantioselectivity for a variety of indoline products containing both triand tetrasubstituted ste...
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