Catalysis and Organic Synthesis Laboratory

Research Interest

Organic molecules are invariably needed to be synthesized in the laboratory to solve exponentially increasing contemporary challenges of human civilization. To solve the paradox of synthesizing the desired product with satisfactory yield and selectivity by using the least amount of valuable natural resources, the more efficient catalytic (rather than stoichiometric) pathways are meant to be adopted. In the past few decades a flock of transition metals have been extensively explored owing to their high catalytic activities. Gold, owing to its exceptional stability and magnificent lustrous property, is connected with human civilization as an emblem of beauty, wealth and power since the genesis of known history. It is this exclusive stability that might have created a perennial misconception amongst the scientific community that it is too inert to be used as a catalyst in organic reactions and was exiled as a “catalytically dead” metal. Interestingly, in the late 20th century when it is recognized as an exceptionally strong “π-Lewis acid”, it has emerged as a catalyst of choice for selective activation of carbon-carbon multiple bonds. Since then the field has witnessed a renaissance in homogeneous catalysis and became a topic of intense research around the world. This proliferation of gold catalysis is generally viewed as an unexpected development and even described as a “Black Swan Event” in organic synthesis

Ligand Enabled Gold Redox Catalysis

In transition-metal catalysis, oxidative addition of aryl halides typically relies on careful ligand design. Similarly, in gold catalysis, hemilabile bidentate ligands stabilize square-planar Au(III) intermediates, facilitating oxidative addition and enabling Au(I)/Au(III) redox catalysis for various organic transformations.

Representative Publications

Electrochemical Gold Redox Catalysis

Electrochemical gold catalysis has emerged as an effective strategy for promoting oxidative transformations without the need for sacrificial oxidants. Through anodic oxidation, this approach enables access to the challenging Au(I)/Au(III) redox cycle and allows the controlled generation of reactive Au(III) intermediates. Consequently, electrochemical gold catalysis facilitates diverse cross-coupling and difunctionalization reactions, highlighting its potential in modern synthetic chemistry.  

Representative Publications

External Oxidant Mediated Gold Redox catalysis

External oxidant-mediated gold redox catalysis represents a well-established approach for accessing Au(I)/Au(III) catalytic cycles, enabling a broad range of oxidative processes in organic synthesis. The development of oxidative gold redox catalysis began with the use of external oxidants such as Selectfluor™, hypervalent iodine reagents (PIDA, PIFA, EBX, IBX, CpBXs, etc.), and peroxides. In this strategy, stoichiometric oxidants facilitate the oxidation of Au(I) to Au(III), thereby leveraging the reactivity of Au(III) intermediates to enable diverse transformations.

Representative Publications

Asymmetric Gold Redox Catalysis

Ligand-enabled asymmetric Au(I)/Au(III) catalysis has emerged as an efficient and versatile platform for enantioselective organic transformations. The careful design of ligands plays a crucial role in controlling reactivity and stereochemical outcomes by stabilizing reactive intermediates and guiding the formation of chiral products. As a result, this strategy enables high levels of enantioselectivity and has significantly expanded the scope and utility of gold redox catalysis in general organic synthesis.  

Representative Publications

Gold Photoredox Catalysis

Harnessing light in transition-metal catalysis has emerged as an important strategy for enabling reactivity beyond conventional thermal pathways. In this context, visible-light-driven redox catalysis has been successfully extended to gold systems to facilitate Au(I)/Au(III) redox cycles. By employing photoredox catalysts in combination with gold complexes and suitable radical precursors, light-driven approaches enable the oxidation of Au(I) species and promote diverse gold-catalyzed transformations. In addition, dinuclear gold catalysis has emerged as an alternative strategy, wherein cooperative interactions between two gold centers facilitate redox processes and enable efficient access to reactive intermediates, thereby expanding the field of gold redox catalysis.

Representative Publications