Iron(ii)-catalyzed C-2 cyanomethylation of indoles and pyrroles via direct oxidative cross-dehydrogenative coupling with acetonitrile derivatives

Abstract

A novel and efficient approach for the C(sp2)–H/C(sp3)–H oxidative coupling of indoles and pyrroles with acetonitrile derivatives was reported by using the Fe(ii) complex.

Stereoselective synthesis of sulfur-containing β-enaminonitrile derivatives through electrochemical Csp3–H bond oxidative functionalization of acetonitrile

“…Recently, free radical-initiated α-C–H functionalization of alkyl nitriles has attracted attention (Fig. 1a) 16,17 . Nevertheless, these methods require excess equivalents of strong oxidants (peroxides), metal-based oxidants (Ag + , Mn 3+ ), or single-electron transfer reagents (diazonium salts).…”

Reaction Medium as the Installing Reservoir for Key Functionalities in the Molecules

“…CNor . CH 2 CN radicals, either via metals such as Cu/Ag, Cu, Mn, Fe, Pt/TiO 2, or via some metal‐free radical generators such as TBPB . Similarly generation of CN − anion was achieved using various systems such as Cu, NaH .…”

Fe‐Catalyzed Intramolecular Cross‐Dehydrogenative Arylation (CDA), Efficient Synthesis of 1‐Arylnaphthalenes and 4‐Arylcoumarins

“…[53 -60] Many excellent works of iron-catalyzed CDC reactions involve C(sp 3 )H bond activation have been reported. [36,[61][62][63][64][65][66][67][68][69][70][71] In 2009, we developed a Fe-catalyzed cross-dehydrogenation coupling reaction of electron-rich aromatic hydrocarbons and diphenylmethane [36] (Scheme 1,b). Based on our continuous research on the field of transition-metalcatalyzed oxidative coupling of unactivated CÀ H bonds, [36,72,73] we here developed an inexpensive, readily available FeCl 3 /DDQ system to efficiently catalyze the tandem cross-dehydrogenative arylation/ oxidation reaction of 1,4-diphenylbutane and (3phenoxypropyl) benzene towards the synthesis of 1arylnaphthalenes and 4-arylcoumarins (Scheme 1,c).…”

“…Among all of the reported transition metals, Fe was brought into focus because of its low toxicity, popular price, and environmentally benign features [53–60] . Many excellent works of iron‐catalyzed CDC reactions involve C( sp 3 )H bond activation have been reported [36,61–71] . In 2009, we developed a Fe‐catalyzed cross‐dehydrogenation coupling reaction of electron‐rich aromatic hydrocarbons and diphenylmethane [36] ( Scheme 1 ,b ).…”