Core Viewpoint - The article discusses advancements in chiral recognition and catalytic conversion of macromolecules, particularly focusing on the successful application of enzyme-like catalysts for the chiral recognition of polylactic acid (PLA) and its selective depolymerization into chiral lactide monomers [4][9]. Group 1: Chiral Recognition and Catalysis - Chirality is a fundamental characteristic in nature, with enzymes playing a crucial role in the selective recognition and transformation of chiral molecules, ensuring efficient metabolic pathways and accurate genetic information transfer [2]. - The research highlights the challenges in asymmetric catalysis for large molecules due to their complex spatial structures, which require advanced synthetic catalysts for effective chiral recognition [3]. - The Qingdao Energy Institute's research center has made significant progress in chiral recognition and catalytic conversion, achieving selective polymerization of chiral monomers in previous studies [3]. Group 2: Research Achievements - The research team successfully utilized a bis-salen-Al catalyst to achieve chiral recognition and stereoselective depolymerization of PLA, marking a significant advancement in the field [4]. - The study revealed that the structural characteristics of the catalyst are key to achieving chiral recognition and catalytic conversion of polymers, with a depolymerization rate difference of up to 37.5 times between different PLA configurations [8]. - The research findings were published in Nature Communications and received high praise from reviewers, being recognized as a notable conceptual advancement in extending asymmetric catalysis to macromolecules [9].

Core Viewpoint - The article discusses a significant advancement in the asymmetric synthesis of N-chiral compounds, highlighting a collaborative research effort that successfully achieved the first catalytic asymmetric synthesis of these compounds, which is crucial for future studies in this area [4][5]. Group 1: Research Background - The research was conducted by a team from Southern University of Science and Technology and UCLA, focusing on controlling pyramidal nitrogen chirality through asymmetric organocatalysis [4]. - The study addresses the challenges associated with the instability of nitrogen stereocenters and the limited success in asymmetric synthesis of non-cyclic N-chiral compounds [5][7]. Group 2: Methodology and Findings - The team proposed a method to synthesize challenging non-cyclic N-chiral chlorohydroxylamines through asymmetric chlorination reactions, capturing unstable chiral intermediates to obtain more stable N-chiral molecules [7]. - A significant breakthrough was achieved using a chiral phosphoric acid catalyst, leading to the successful synthesis of 21 N-stereocenters with high enantioselectivity [8]. - The research demonstrated that introducing a rigid bicyclic structure near the nitrogen atom significantly improved the stability of the configuration, reducing racemization [10]. Group 3: Mechanism and Results - The study confirmed that the key step for stereoselectivity was the chlorination reaction, followed by an intramolecular nucleophilic substitution that adhered to the S N 2 mechanism, ensuring effective transfer of chirality [10]. - The final products exhibited enantiomeric excess values greater than 90%, showcasing the method's effectiveness and broad applicability [10].