Rhodium(III)-Catalyzed Regioselective C3–H Acylmethylation of [2,2′-Bipyridine]-6-carboxamides with Sulfoxonium Ylides

Abstract

A rhodium(III)-catalyzed C−H acylmethylation of tridentate [2,2′-bipyridine]-6-carboxamides was developed. A variety of [2,2′-bipyridine]-6-carboxamides could be monoalkylated exclusively at the C3 position with sulfoxonium ylides as carbene precursors, giving 3-alkylated products in high yields. This protocol proceeds through a rollover cyclometalation pathway, has a broad range scope of substrates, and exhibits excellent functional group tolerance.

Co(III), Rh(III) & Ir(III)‐Catalyzed Direct C−H Alkylation/Alkenylation/Arylation with Carbene Precursors

“…Under the standard conditions, both substrates are well tolerated and produced corresponding products in good yields with excellent selectivity (Scheme 16). [28] …”

Asymmetric transformations from sulfoxonium ylides

“…26,27 From the products provided in the C-H activation step, many post functionalization reactions can be performed to generate structurally diverse heterocycles and carbocycles (Scheme 2F and G). [28][29][30][31][32][33][34][35][36] Important progress has also been made with regards to metal or carbenefree reactions by exploring the potential nucleophilicity of the sulfoxonium ylides. Some representative examples are the insertion reactions, [37][38][39] a-halogenations, 40 alkylations, 41 cyclizations, [42][43][44][45] ring CH 2 -homologations and epoxide ring opening reactions (Scheme 2H-L).…”

Rh(iii)-catalyzed C–H annulation of sulfoxonium ylides with iodonium ylides towards isocoumarins

“…9 In this field, the transition metal (Rh, 10 Ru, 11 Pd 12 and others 13 ) catalyzed C–H functionalization of arenes and coupling with sulfoxonium ylides holds great potential to manufacture various heterocycles. Sulfoxonium ylides have been predominantly used as carbonylation reagents 14 or C2 15 synthons in annulation reactions, usually as C4 16 synthons and occasionally as C3 17 synthons. For instance, in 2019, Yu and co-workers 18 demonstrated a rhodium( iii )-catalyzed annulated coupling of sulfoxonium ylides with allenoates towards the synthesis of 2 H -cyclopropa[ b ]-naphthalen-2-ones in the presence of a Ag salt (Scheme 1a).…”