A remote C–C bond cleavage–enabled skeletal reorganization: Access to medium-/large-sized cyclic alkenes

Abstract

We report a radical-mediated skeletal reorganization for the synthesis of medium-/large-sized cyclic alkenes.

Intermolecular Radical Fluoroalkylative Olefination of Unactivated Alkenes

“…[1][2][3][4][5][6][7] Most of the current approaches rely highly on the properties of alkenes; activated alkenes are usually suitable substrates, for example, styrenes, enol ethers, enamines, acrylates, and so forth, owing to the presence of p-π conjugation that stabilizes nascent alkyl radicals arising from radical addition to alkenes. To surmount the obstacles in radical difunctionalization of unactivated alkenes, the strategy of remote functional group migration (FGM) was unveiled, [8][9][10][11][12] and has been applied successfully to a set of elusive alkene transformations, including cyanation, 13,14 (hetero)arylation, [15][16][17][18][19] alkynylation, 20,21 alkenylation, [22][23][24][25][26] acylation, 27,28 and oximination. [28][29][30] Incorporation of a fluoroalkyl group (CF 3 , CF 2 R, or CFRR') to bioactive molecules usually rendered a substantial change in lipophilicity, metabolic stability, and other bioactivities.…”

“…[28][29][30] Incorporation of a fluoroalkyl group (CF 3 , CF 2 R, or CFRR') to bioactive molecules usually rendered a substantial change in lipophilicity, metabolic stability, and other bioactivities. [31][32][33][34][35] Recently, Liu et al 22 and Studer 23 reported elegant examples of fluoroalkylative olefination of unactivated alkenes utilizing FGM (Scheme 1a). Strategic placement of allylic alcohol moiety is a requisite for intramolecular alkenyl migration.…”

Skeletal reorganization divergence of N-sulfonyl ynamides

“…Meanwhile, Liu and co-workers established a skeletal reorganization protocol of olefine via a radical-initiated cyclization/1, n ( n = 3, 4, 5) vinyl migration cascade for accessing medium- and large-sized cycles, which are ubiquitous structural motifs in natural products and pharmaceutical agents (Fig. 1c ) 12 . Very recently, Zhu and co-workers reported a novel skeletal reorganization of kojic acid- or maltol-derived alkynes under Indium catalysis, which provided an expeditious access to valuable hydroxylated benzofurans (Fig.…”

Synthesis of Multisubstituted Benzimidazolones via Copper-Catalyzed Oxidative Tandem C–H Aminations and Alkyl Deconstructive Carbofunctionalization

“…As such, the search for new C–H amination strategies involving free amines as the aminating agents in the absence of directing groups still remains a highly demanding goal. In terms of carbofunctionalization, much effort has been directed during the past decade toward the difunctionalization of alkenes (Qin et al., 2016, Shen et al., 2013, Shen et al., 2016, Li et al., 2016) and alkynes (Li et al., 2017, Urgoitia et al., 2017, Rubinstein et al., 2014, Rao et al., 2017). Moreover, carbofunctionalization via the cleavage of unsaturated C–C bonds (Sagadevan et al., 2017, Shen et al., 2013, Shen et al., 2016, Qin et al., 2016) has also been nicely established.…”