Design and Preparation of a Bifunctional Nanobiohybrid Catalyst by Combining Palladium and α‐Amylase Enzyme: Application in One‐pot Chemoenzymatic Catalysis

Abstract

Chemoenzymatic approach which combines chemical and bio‐catalyst has proven very useful in synthetic chemistry, however, mutual deactivation of chemical and bio‐catalyst when employed in the same pot is still a challenge. In this context, the development of nanobiohybrid catalysts has played an important role and overcome the issue of mutual deactivation between catalysts to a certain extent. Herein, we design and synthesized a novel heterogeneous nanobiohybrid catalyst comprising palladium nanoparticles and α‐amylase from Aspergillus oryzae immobilized onto halloysite nanotubes as a solid heterogeneous support. Further, the wider applicability of the developed nanobiohybrid catalyst is revealed in the one‐pot chemoenzymatic synthesis of functionalized biphenyls and bis(indolyl)methanes which consist of Pd‐catalyzed Suzuki‐Miyaura coupling and α‐amylase mediated aza‐Michael addition or electrophilic substitution reactions respectively. Further, the robustness and generality of the developed one‐pot chemoenzymatic synthesis are demonstrated by incorporating different substitutions at the starting materials and obtaining the corresponding products in moderate to good yields.