Donor‐Acceptor Cyclopropanes in the Synthesis of Carbocycles

Abstract

Donor‐acceptor cyclopropanes not only participate in a broad range of ring openings with nucleophiles, electrophiles, radical and red‐ox agents, but also are excellent substrates for various (3+n)‐cycloaddition and (3+n)‐annulation processes. Moreover, under treatment with Lewis acid donor‐acceptor cyclopropanes can produce new ring systems via isomerization or cyclodimerization. Authors’ contribution to the synthesis of diverse carbocycles from donor‐acceptor cyclopropanes is summarized in this account.

Asymmetric Catalytic Reactions of Donor–Acceptor Cyclopropanes

“…Less reactive D-A cyclopropanes bearing an alkyl donor, or containing only one acceptor group have been less explored. Only few asymmetric [3+ +2] annulations of D-A cyclopropanes have been performed by radical reactions.H ere also should be space for future developments of enantioselective modifications of already well-studied racemic transformations of D-A cyclopropanes,f or example,i somerization, [52] homo-Nazarov cyclizations, [53] and vinylcyclopropane-cyclopentene rearrangements. [54] In this regard, for the Lewis acid catalyzed reactions,i tm ost certainly not the solution to introduce ac hiral ligand to aw orking catalytic system to render transformations enantioselective,a st he catalytic activity of the Lewis acid completely changes once coordinated with achiral Lewis base.Therefore,the development of novel strategies and new catalyst systems still remains appealing.F urthermore,t hese enantioselective transformations can be expected to be suitable for application in the total syntheses of natural products.…”

Transition-Metal-Free [3+2] Dehydration Cycloaddition of Donor-Acceptor Cyclopropanes With 2-Naphthols

“…Among various methods, domino ring-opening cyclization has recently emerged as a powerful tool for the rapid build-up of molecular complexity (Bhattacharyya et al, 2016;Lin et al, 2017;Sayyad et al, 2017;Yi et al, 2018;Wan and Liu, 2019). As a versatile class of three-atom building blocks, donor-acceptor (D-A) cyclopropanes have experienced an unexpected renaissance in the last 2 decades, which are widely exploited in methodology as well as natural product synthesis (Cavitt et al, 2014;Schneider et al, 2014;Grover et al, 2015;Novikov, 2015;Reiser, 2016;Ivanova and Trushkov, 2019;Werz and Biju, 2020). Due to their property of formation of 1,3-zwitterion intermediates with the help of the ring strain, D-A cyclopropanes could enter multitudinous kinds of chemical transformations with different counterparts in organic synthesis.…”

Ring-Opening Cyclization of Spirocyclopropanes Using Sulfoxonium Ylides

“…4) To date, sulfur ylides 1a and 2a have been widely used in the synthesis of various epoxides, 5,6) cyclopropanes, 7,8) and heterocyclic compounds. [9][10][11] Doubly-activated cyclopropanes are versatile intermediates for the synthesis of a wide range of carbocycles 12) and heterocycles. 13) With this in mind, regioselective ring-opening cyclizations of cyclohexane-1,3-dione-2-spirocyclopropanes 3 have been developed for the synthesis of indole [14][15][16] and benzofuran.…”

“…However, sulfonium ylides used in this reaction were limited to EWG-stabilized ones 1b. Since sulfur ylides with various reactivities have been used in organic synthesis, [5][6][7][8][9][10][11] this study focused on the reaction between different sulfur ylides and spirocyclopropanes. Herein, the ring-opening cyclization of spirocyclopropanes 3 using non-, alkyl-, and phenyl-substituted sulfoxonium ylides 2 as a carbon nucleophile is reported (Chart 2B).…”