Recent Advances in Ru Catalyzed Transfer Hydrogenation and Its Future Perspectives

Over the past few decades, Ru catalyzed transfer hydrogenation (TH) and asymmetric transfer hydrogenation (ATH) reactions of unsaturated hydrocarbons, imine, nitro and carbonyl compounds have emerged as economic and powerful tools in organic synthesis. These reactions are most preferred processes having applications in the synthesis of fine chemicals to pharmaceuticals due to safe handling as these do not require hazardous pressurized H2 gas. The catalytic activity and selectivity of Ru complexes were investigated with a variety of ligands based on pincer NHC, cyclophane, half-sandwich, organophosphine etc. These ligands coordinate to Ru center in a proper orientation with a labile group replaced by H-source (like methanol, isopropanol, formic acid, dioxane, THF), which facilitate the β-hydrogen transfer to generate metal hydride species (Ru-H) and produce desired reduced product. This chapter describes the recent advances in TH and ATH reactions with homogeneous and heterogeneous Ru catalysts having different ligand environments and mechanistic details leading to their sustainable industrial applications.

Design, Synthesis and Characterization of Novel sn-1 Heterocyclic DAGlactones as PKCe Activators

<p>In this study we describe the synthesis and characterization of novel diacylglycerol (DAG)-lactones that bind to protein kinase C (PKC). DAG-lactones proved to be useful templates for the design of potent and selective C1 domain ligands. The ester moiety at <i>sn-1</i> position, a common feature in this template, is relevant for interaction with the PKC C1 domains, although it represents a labile group susceptible to endogenous esterases. Our studies identified the DAG-lactone 10B12 with an isozazole ring as a nanomolar affinity PKC ligand. This compound shows preferential selectivity for PKCepsilon, and strongly activates actin cytoskeleton reorganization into peripheral ruffles in cancer cells, an effect mediated by PKCepsilon. Therefore, introducing a stable isoxazole ring as an ester surrogate in DAG-lactones emerges as a novel structural approach to achieve PKC selectivity.</p><div><br></div>

Design, Synthesis and Characterization of Novel sn-1 Heterocyclic DAGlactones as PKCe Activators

<p>In this study we describe the synthesis and characterization of novel diacylglycerol (DAG)-lactones that bind to protein kinase C (PKC). DAG-lactones proved to be useful templates for the design of potent and selective C1 domain ligands. The ester moiety at <i>sn-1</i> position, a common feature in this template, is relevant for interaction with the PKC C1 domains, although it represents a labile group susceptible to endogenous esterases. Our studies identified the DAG-lactone 10B12 with an isozazole ring as a nanomolar affinity PKC ligand. This compound shows preferential selectivity for PKCepsilon, and strongly activates actin cytoskeleton reorganization into peripheral ruffles in cancer cells, an effect mediated by PKCepsilon. Therefore, introducing a stable isoxazole ring as an ester surrogate in DAG-lactones emerges as a novel structural approach to achieve PKC selectivity.</p><div><br></div>