Metal–free Efficient Method for the Synthesis of N‐(2‐haloethyl)benzamides through the Ring‐opening of2‐oxazolines

Abstract

An efficient, metal-free C-H halogenated method for the synthesis of β-halogenated carboxamides using non-corrosive NXS (X=Cl, Br) as the halogenated source and ammonium sulfocyanide (NH 4 SCN) as the additive was proposed and accomplished. Various substituted 2-oxazolines efficiently afforded the corresponding β-halogenated carboxamides via a ring-opening reaction in good yields. The characteristic features of this reaction include readily available materials, mild reaction conditions and functional groups tolerance.[a] Dr.

Palladium-catalyzed C–H trifluoromethylselenolation of arenes with [Me4N][SeCF3] and an oxidant

“…The ring-opening of the dihydrooxazole moiety in 4f might be caused by the nucleophilic attack of the in situ formed chloride anion from PhICl 2 . 16 To gain insight into the mechanism of this aromatic trifluoromethylselenolation, several control experiments were carried out (see ESI †). Initially, 2-phenylpyridyl palladium acetate dimer (6) was synthesized and used as a reactant or catalyst under the standard conditions.…”

“…The ring-opening of the dihydrooxazole moiety in 4f might be caused by the nucleophilic attack of the in situ formed chloride anion from PhICl 2 . 16…”

Unprecedented transformation from cyclized zwitterionic oxazolidine derivatives to corresponding non-zwitterionic aromatic amides via Vilsmeier reagent in a one-pot reaction: optical property and crystallography

“…Halogenation and ring opening of 4,5-dihydrooxazole-3-ium derivatives into open-chain β-haloamide derivatives are beneficial in organic and medicinal chemistry methodologies. 45–47 Despite Friedel–Crafts halogenation processes, 48 Sandmeyer reaction 49 (on C–X [Cl, Br]), and certain organometallic reagents 50 extensively employed in organic synthetic methodologies, there are very few reports on metal-free carbon-halogenation reactions. 45…”

“…45–47 Despite Friedel–Crafts halogenation processes, 48 Sandmeyer reaction 49 (on C–X [Cl, Br]), and certain organometallic reagents 50 extensively employed in organic synthetic methodologies, there are very few reports on metal-free carbon-halogenation reactions. 45…”

“…Halogenation and ring opening of 4,5-dihydrooxazole-3-ium derivatives into open-chain b-haloamide derivatives are beneficial in organic and medicinal chemistry methodologies. [45][46][47] Despite Friedel-Crafts halogenation processes, 48 Sandmeyer reaction 49 (on C-X [Cl, Br]), and certain organometallic reagents 50 extensively employed in organic synthetic methodologies, there are very few reports on metal-free carbonhalogenation reactions. 45 With the aforementioned perspective, herein, we synthesized two cyclized derivatives, namely dicyano(4-(4,5-dihydrooxazole-3-ium-2-yl)phenyl)methanide (DDPM) [1] [4] were generated on further reaction of [1] and [2] with (COCl) 2 and DMF.…”