Abstract
The first highly enantioselective catalytic protocol for the reductive coupling of ketones and hydrazones is reported. These reactions proceed through neutral ketyl radical intermediates generated via a concerted proton-coupled electron transfer (PCET) event jointly mediated by a chiral phosphoric acid catalyst and the photoredox catalyst Ir(ppy)2(dtbpy)PF6. Remarkably, these neutral ketyl radicals appear to remain H-bonded to the chiral conjugate base of the Brønsted acid during the course of a subsequent C-C bond-forming step, furnishing syn 1,2-amino alcohol derivatives with excellent levels of diastereo- and enantioselectivity. This work provides the first demonstration of the feasibility and potential benefits of concerted PCET activation in asymmetric catalysis.
Original language | English (US) |
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Pages (from-to) | 17735-17738 |
Number of pages | 4 |
Journal | Journal of the American Chemical Society |
Volume | 135 |
Issue number | 47 |
DOIs | |
State | Published - Nov 27 2013 |
All Science Journal Classification (ASJC) codes
- General Chemistry
- Biochemistry
- Catalysis
- Colloid and Surface Chemistry