Enantioselective Pd(II)-catalyzed aerobic oxidative amidation of alkenes and insights into the role of electronic asymmetry in pyridine-oxazoline ligands.
نویسندگان
چکیده
Enantioselective intramolecular oxidative amidation of alkenes has been achieved using a (pyrox)Pd(II)(TFA)(2) catalyst (pyrox = pyridine-oxazoline, TFA = trifluoroacetate) and O(2) as the sole stoichiometric oxidant. The reactions proceed at room temperature in good-to-excellent yields (58-98%) and with high enantioselectivity (ee = 92-98%). Catalyst-controlled stereoselective cyclization reactions are demonstrated for a number of chiral substrates. DFT calculations suggest that the electronic asymmetry of the pyrox ligand synergizes with steric asymmetry to control the stereochemical outcome of the key amidopalladation step.
منابع مشابه
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ورودعنوان ژورنال:
- Organic letters
دوره 13 11 شماره
صفحات -
تاریخ انتشار 2011