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Bridged cyclobutanes and sulfur heterocycles are currently under intense investigation as building blocks for pharmaceutical drug design. Two formal cycloaddition modes involving bicyclobutanes (BCBs) and pyridinium 1,4‐zwitterionic thiolate derivatives were described to rapidly expand the chemical space of sulfur‐containing bridged cyclobutanes. By using Ni(ClO4)2 as the catalyst, an uncommon higher‐order (5+3) cycloaddition of BCBs with quinolinium 1,4‐zwitterionic thiolate was achieved with broad substrate scope under mild reaction conditions. Furthermore, the first Lewis acid‐catalyzed asymmetric polar (5+3) cycloaddition of BCB with pyridazinium 1,4‐zwitterionic thiolate was accomplished. In contrast, pyridinium 1,4‐zwitterionic thiolates undergo an Sc(OTf)3‐catalyzed formal (3+3) reaction with BCBs to generate thia‐norpinene products, which represent the initial instance of synthesizing 2‐thiabicyclo[3.1.1]heptanes (thia‐BCHeps) from BCBs. Moreover, we have successfully used this (3+3) protocol to rapidly prepare thia‐BCHeps‐substituted analogues of the bioactive molecule Pitofenone. Density functional theory (DFT) computations imply that kinetic factors govern the (5+3) cycloaddition reaction between BCB and quinolinium 1,4‐zwitterionic thiolate, whereas the (3+3) reaction involving pyridinium 1,4‐zwitterionic thiolates is under thermodynamic control. [ABSTRACT FROM AUTHOR]

Cycloadditions. Bicyclo[n.1.1]alkanes show great promise in substituting planar aromatic rings, akin to the "butterfly effect". In their Research Article (e202408578), Jian‐Jun Feng et al. present a Lewis acid‐catalyzed cycloaddition of bicyclobutanes (butterfly conformation) with 2D pyridinium thiolate derivatives...By Yuanjiu Xiao; Feng Wu; Lei Tang; Xu Zhang; Mengran Wei; Guoqiang Wang and Jian‐Jun FengReported by Author; Author; Author; Author; Author; Author; Author [Extracted from the article]