ABSTRACT
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.
ABSTRACT
The synthesis of 1,3,4-trisubstituted pyrroles via visible-light mediated photoredox catalyzed condensation of arylazides and aldehydes has been reported herein. The methodology avoids the use of stoichiometric oxidants and provides the corresponding N-containing arenes in good yields (up to 78%) and mild conditions. Mechanistic rationale is provided via a dedicated and combined spectroscopic/experimental investigations.
ABSTRACT
The site-selective thio-allylation of electron-deficient 1,2-dienes is documented under scandium catalysis. The methodology enables the realization of α-ß unsaturated, ß-thio, γ-allyl carboxylic acid derivatives via a one-pot Lewis acid promoted Michael addition/[3,3]-sigmatropic rearrangement sequence (20 examples) in high yields (up to 95%). Full rationalization of the reaction mechanism and stereochemical outcome is provided via DFT simulations.
