Theoretical Model for N-Heterocyclic Carbene-Catalyzed Desymmetrizing [4 + 1] and [4 + 2] Annulations of an Enal and Aryldialdehyde with 1,3-Cyclopentenedione

• DOI: 10.1021/acs.orglett.1c00270
• Publication Date: 2021-03-17T07:31:58Z
• Authors: Xinghua Wang; Shi-Jun Li; Ya-Nan Wang; Donghui Wei; Yu Lan
• Keywords: 01 natural sciences; 0104 chemical sciences

N-Heterocyclic carbene (NHC) catalyzed desymmetrizing reactions of olefins have rapidly developed in recent years; however, the origins of the chemo- and stereoselectivities of these reactions remain poorly understood. Herein, we propose a mechanistic map for these reactions to predict how chemo- and stereoselectivities are controlled by different active intermediates (i.e., Breslow and acylazolium intermediates). Remarkably, our findings contradict a previous proposition that product structures are determined by a transformation between a pair of isomers.