Nickel-Catalyzed Deamidative Step-Down Reduction of Amides to Aromatic Hydrocarbons

To date, cleavage of the C−N bond in aromatic amides has been achieved in molecules with a distorted constitutional framework around the nitrogen atom. In this report, a nickel-catalyzed reduction of planar amides to the corresponding lower hydrocarbon homologue has been reported. This involves a one-pot reductive cleavage of the C−N bond followed by a tandem C−CO bond break in the presence of a hydride source. Substrate scope circumscribes deamidation examples which proceed via oxidative addition of nickel in the amide bonds of nontwisted amides. Mechanistic studies involving isolation and characterization of involved intermediates via different spectroscopic techniques reveal a deeper introspection into the plausible catalytic cycle for the methodology

Photoinduced Regioselective Olefination of Arenes at Proximal and Distal Sites

The Fujiwara-Moritani reaction has had a profound contribution in the emergence of contemporary C−H activation protocols. Despite the applicability of the traditional approach in different fields, the associated reactivity and regioselectivity issues had rendered it redundant. The revival of this exemplary reaction requires the development of a mechanistic paradigm that would have simultaneous control on both the reactivity and regioselectivity. Often high thermal energy required to promote olefination leads to multiple site functionalization. To this aim we established a photoredox catalytic system constituting a merger of palladium/organo-photocatalyst that forges oxidative olefination in an explicit regioselective fashion of diverse arenes and heteroarenes. Visible light plays a significant role in executing ‘regio-resolved’ Fuijiwara-Moritani reaction without the requirement of silver salts and thermal energy. The catalytic system is also amenable towards proximal and distal olefination aided by respective directing groups (DGs), which entails the versatility of the protocol in engaging the entire spectrum of C(sp2)−H olefination. Furthermore, streamlining the synthesis of natural products, chiral molecules, drugs and diversification through late-stage functionalization’s underscore the importance of this sustainable protocol. The photoinduced attainment of this regioselective transformation is mechanistically established through control reactions, kinetic studies and theoretical calculations