Applications of transition state calculations in the key cyclization of small molecule natural product synthesis

The diversification of the conformation and configuration of the carbocyclic skeleton of natural products is an important reason for the diversity and complexity of the structure of natural products. The corresponding cyclization synthesis has attracted much attention. Computational chemistry approaches have the advantages of non-toxic, harmless and relatively low cost, and they are increasingly used to model and understand molecular phenomena. The reaction mechanism and thermodynamic parameters determine the feasibility of the cyclization and the enantioselectivity of the cyclization products. The transition state calculations can provide these thermodynamic parameters, which helps to elucidate the cyclization mechanism, calculate the reaction rationality, predict the performance of the new synthesis method and provide a basis for the comprehensive synthesis design