“…[9] To date, an assortment of TMM dipole precursors has been developed to enable the efficient construction of cyclic compounds (Scheme 1a), encompassing methylene cyclopropanes, [10] 2-substituted allyl carbonates (Trost-TMM), [9h,11,12] γ -methylideneδ -valerolactones, [8g,13] 2-methylidenetrimethylene carbonates, [14] pyrrolidines, [15] 2-methylene-1-indanols. [16] Among various types of TMM dipole precursors, Trost-TMM is the most extensively investigated one, which served as an efficient three-carbon unit in cycloadditions. [9h] In this field, our group successfully realized several asymmetric [3 + 4] cycloadditions of Trost-TMM precursors with different 4atom synthons, furnishing a series of fused azepines or cycloheptanes with excellent regio-, diastereo-and enantioselectivities in recent years (Scheme 1b).…”