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The enantioselective trifluoromethylthiolation of β-ketoesters using chiral copper-boxmi complexes as catalysts is reported. A number of α-SCF3-substituted β-ketoesters have been obtained with up to >99% enantiomeric excess (ee), and the trifluoromethylthiolated products were then transformed diastereoselectively to α-SCF3-β-hydroxyesters with two adjacent… (More)
A new class of chiral tridentate N-donor pincer ligands, bis(oxazolinylmethylidene)isoindolines (boxmi), was synthesized in three steps starting from readily available phthalimides. Their reaction with ethyl (triphenylphosphoranylidene)acetate by means of a key-step Wittig reaction gave the ligand backbones, which were condensed with amino alcohols and then… (More)
The first example of Fe-catalyzed enantioselective azidations of β-keto esters and oxindoles using a readily available N3-transfer reagent is reported. A number of α-azido-β-keto esters were obtained with up to 93% ee, and this methodology also generates 3-substitued 3-azidooxindoles with high enantioselectivities (up to 94%).
Tridentate monoanionic ligands known as "pincers" have gained a prominent place as ligands for transition metals and, more recently, for main-group metals and lanthanides. They have been widely employed as ancillary ligands for metal complexes studied inter alia in bond activation steps relevant to catalytic processes. The central formally anionic aryl or… (More)
Cu-catalyzed enantioselective alkylation of β-ketoesters using alcohols for in situ preparation of alkylating reagents is reported. A number of functionalized β-ketoesters containing a quaternary carbon stereocenter are obtained with up to 99% ee. The alkylation products derived from 2-substituted allylic alcohols or their corresponding iodides can then be… (More)
Whereas the stereochemical rigidity of the coordination sphere of boxmi/Cu(II) catalysts is key to achieving high enantioselectivity in the electrophilic alkylation of β-ketoesters, this pathway is outperformed by a radical process for the corresponding catalytic transformation of oxindoles, giving rise to racemic products. For the corresponding Zn(II)… (More)
Enantioselective Cu-catalyzed trifluoromethylation of β-ketoesters using commercially available trifluoromethylating reagents is reported. A number of α-CF(3) β-ketoesters are obtained with up to 99% ee. The trifluoromethylated products were then transformed diastereoselectively to α-CF(3) β-hydroxyesters with two adjacent quaternary stereocenters via a… (More)
The chiral iridium porphyrin [Ir((-)-D(4)-Por*)(Me)(EtOH)] displays excellent reactivity and stereoselectivity towards carbene insertion to C-H and Si-H bonds, affording corresponding products in high yields (up to 96%) and high enantioselectivities (up to 98% ee).