22618-50-4Relevant articles and documents
Visible-Light Photoredox Catalyzed Dehydrogenative Synthesis of Allylic Carboxylates from Styrenes
Bandini, Marco,Battaglioli, Simone,Liu, Yang,Lombardi, Lorenzo,Menichetti, Arianna,Montalti, Marco,Valenti, Giovanni
, p. 4441 - 4446 (2021/06/28)
The visible-light photoredox/[Co(III)] cocatalyzed dehydrogenative functionalization of cyclic and acyclic styryl derivatives with carboxylic acids is documented. The methodology enables the chemo- and regioselective allylic functionalization of styryl compounds, leading to allylic carboxylates (32 examples) under stoichiometric acceptorless conditions. Intermolecular as well as intramolecular variants are documented in high yields (up to 82%). A mechanistic rationale is also proposed on the basis of a combined experimental and spectroscopic investigation.
Enantioselective photoredox catalysis enabled by proton-coupled electron transfer: Development of an asymmetric aza-pinacol cyclization
Rono, Lydia J.,Yayla, Hatice G.,Wang, David Y.,Armstrong, Michael F.,Knowles, Robert R.
, p. 17735 - 17738 (2014/01/06)
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 Bronsted 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.
Tailoring aqueous solvents for organic reactions: Heck coupling reactions in high temperature water
Gron,Tinsley
, p. 227 - 230 (2007/10/03)
High temperature water is demonstrated to be an effective solvent for Heck coupling reactions of aromatic halides with cyclic alkenes without the addition of co-solvents or specialized ligands. Reactions in the presence of LiCl and quaternary ammonium salts indicate that the reaction takes place in the aqueous phase.