Synthesis of 3′- Or 4′-Alkenylbenzocrown Ethers

Abstract

Palladium(0) catalyzed alkenylation of 3′- or 4′-iodo- (or bromo-) benzocrown ethers are found to be a convenient procedure for the introduction of alkenyl groups (–CH=CH–R; R=Ph, COOEt and COOH). Iodination at 3′-position of benzocrown ethers could be achieved in good yield by the use of 4′-t-butyl derivatives.

Halogenation of Benzocrown Ethers by Hypohalites in Aqueous Solutions

“…Sufficient mobility of bromine and iodine atoms in the aromatic fragments of these macrocycles enables ease of further transformations into acetylene, [3][4][5] vinyl, [4][5] n-alkyl, n-hydroxyalkyl, [6] bioactive ammonium and phosphonium [7] derivatives, which are hard or inaccessible by other ways, and also crown heterocycles, [8] bis-benzocrown ethers, [3,6] etc. HBCE have great potential as materials for the synthesis of new types of polymers with selective sorption, [9] original nanolayers, [1] considerably increasing products' wear resistance, etc.…”

“…HBCE have great potential as materials for the synthesis of new types of polymers with selective sorption, [9] original nanolayers, [1] considerably increasing products' wear resistance, etc. The iodination usually is conducted in the systems, containing strong oxidants or expensive reagents, namely, I 2 -HIO 3 -H 2 SO 4 , [10,11] I 2 -СF 3 COOAg, [5] trimethylbenzylammonium dichloro iodide-CH 3 COOH-ZnCl 2 . [12] In the bromination process the molecular bromine (Br 2 ) is used or, in some cases, N-bromosuccinimide (NBS).…”

A Simple Method for Iodination of Benzo- and Dibenzocrown Ethers

“…Иодзамещенные бензо-(БКЭ) и дибензокраунэфиры (ДБКЭ) легко трансформируются в труднодоступные ацетиленовые, [1][2][3] винильные, [4,5] н-алкильные, н-гидроксиалкильные, [6] биологически активные аммониевые и фосфониевые [7] производные, а также краун-гетероциклы, [8] бис-бензокраун-эфиры [3,6] и др.…”

The Peculiarities of the Reaction of Benzo- and Dibenzocrown Ethers with N-Halogenosuccinimides

“…Bromo-and iodosubstituted benzo-(BCE) and dibenzocrown ethers (DBCE) easily transform into either hardly obtainable or unavailable by other methods acetylenic, [1][2][3] vinyl, [4,5] n-alkyl, n-hydroxyalkyl, [6] phosphorus containing derivatives, [7] and also crown heterocycles, [8] bis-benzocrown ethers, [3,6] etc. Synthesis and properties of corresponding chloroanalogues are almost not researched.…”

“…[9,10] Molecular bromine, [11][12][13][14][15] rarely -N-bromosuccinimide [16] are commonly employed for the bromination, and as for iodination, oxidants are necessary. Therefore, it is carried out in the systems: I 2 -HIO 3 -H 2 SO 4 , [17,18] I 2 -СF 3 COOAg, [5] I 2 (HI)-H 2 O 2 [19] or trimethylbenzylammonium iodine dichloride-ZnCl 2 -CH 3 COOH. [20] Intensification of substance transformation relates to one of the main problems of contemporary organic chemistry.…”