Palladium(II)‐Catalyzed C3‐Selective Friedel–Crafts Reaction of Indoles with Aziridines

Abstract

The [PdCl 2 (MeCN) 2 ]-catalyzed C3-selective Friedel-Crafts reactiono f2 ,2-disubstituted and 2-aryl-N-tosylaziridines with indoles is reported. For the 2,2-disubstituted substrates, [PdCl 2 (MeCN) 2 ]a lone, without any ancillary ligands, is an efficient catalyst for the ring-opening reaction. The presence of 1,4-benzoquinone as an additive was found to en-hance the ring-opening reactiono ft he less-reactive 2-arylaziridines. This reaction displayed ab road substrate scope with respect to the indole substrate and is operationally simple.F inally,w hen 1,3-dimethylindole was employed as as ubstrate, the de-aromatized pyrroloindoline product was obtained in high yield and good diastereoselectivity.[a] J.

Organocatalytic Olefin Aziridination via Iminium-Catalyzed Nitrene Transfer: Scope, Limitations, and Mechanistic Insight

“…1 H NMR (598 MHz, CDCl 3 ) δ 7.85 (d, J = 7.9 Hz, 2H), 7.41 (d, J = 8.3 Hz, 2H), 7.34 (d, J = 7.9 Hz, 2H), 7.09 (d, J = 8.2 Hz, 2H), 3.72 (dd, J = 7.0, 4.5 Hz, 1H), 2.98 (d, J = 8.1 Hz, 1H), 2.44 (s, 3H), 2.34 (d, J = 4.4 Hz, 1H). Matches literature values …”

“…Matches literature values. 26 2-(4-Iodophenyl)-N-tosylaziridine (20). Prepared from 4-iodostyrene using the general procedure for aziridination.…”

“…Yellow solid (64.4 mg, 0.161 mmol, 32%). 1 26 2-(4-Cyanophenyl)-N-tosylaziridine (21). Prepared from 4-cyanostyrene using the general procedure for aziridination.…”

Fe(OTf) 3 -catalysed Friedel–Crafts reaction of benzenoid arenes with α,β-unsaturated carbonyl compounds: easy access to 1,1-diarylalkanes

“…A significant drawback of large-scale chemical processes is that a vast amount of waste by-products is produced, and it is still a challenging task in standard protocols to free the by-products from arylated products. Three-member cyclic and reactive intermediates, such as epoxides [ 24 – 32 ], aziridines [ 33 – 47 ] and halonium ions [ 48 – 53 ], or other unstable intermediates [ 54 – 58 ] derived in situ from alkenes have also been found as potential electrophiles to afford functionalized Friedel–Crafts alkylated products. Another important strategy to afford 1,1-diarylalkanes is Friedel–Crafts-type hydroarylation reaction with olefins.…”

“…in standard protocols to free the by-products from arylated products. Three-member cyclic and reactive intermediates, such as epoxides [24][25][26][27][28][29][30][31][32], aziridines [33][34][35][36][37][38][39][40][41][42][43][44][45][46][47] and halonium ions [48][49][50][51][52][53], or other unstable intermediates [54][55][56][57][58] derived in situ from alkenes have also been found as potential electrophiles to afford functionalized Friedel-Crafts alkylated products. Another important strategy to afford 1,1diarylalkanes is Friedel-Crafts-type hydroarylation reaction with olefins.…”