Azepines azepane

Azepanes and azepanones continue to attract attention synthetically because of their incorporation in compounds of biological significance. A new diastereoselective and enantioselective lithiation - addition methodology has been described to provide access to the azepine precursors 25 (Ar1 = jb-BrPh, Ar = p-MeOPh)) these were then converted into 27 via 26, and subsequently to the further substituted azepan-2-ones 30 via 28 and 29 <06JA2178>. 

A dominant feature of the type c ring-construction approach to azepine systems has been ruthenium-catalyzed ringclosing metathesis reactions. Examples include the synthesis of the azepine derivative 157 from 156 using either the Grubbs type I catalyst 159 or type II 160. The diene precursor 156 was prepared in turn from 154 via 155, as shown in Scheme 21. Hydrogenation of the C-C double bond in 157 afforded the azepane 158 <2005SL631>. 

Chemical Names S-Ethyl azepane-l-carbothioate S-Ethyl perhydroazepine-l-carbothioate S-Ethyl perhydroazepine-l-thiocarboxilate S-Ethyl hexa-hydro-lH-azepine-1 -carbothioate (9CI)... 

The synthetic power of Ru-catalysed ring closing metathesis reactions has continued to be realized, for example, in the synthesis of the azepine derivative 4 from 3, which was prepared in turn from 1 via 2. Reduction of 4 afforded the azepane 1 <05SL631>. 

Azepan-2-one (hexano-6-lactam, --caprolactam, 28) is industrially the most important azepine derivative. It is used in the production of perlon and is synthesized by Beckmann rearrangement of cyclohexanone oxime. Structurally related to caprolactam is the CNS stimulant pentetrazole 29 (1,5-pentamethylenetetrazole, see p 217). 

A chiral selenophosphoramide catalyst was employed for the intramolecular cyclization of an alkenyl sulfonamide to achieve the enantioselective formation of N-heterocycles including an azepane derivative via a mechanism proposed to include formation of a three-membered sulfur-containing ring (14JA8915). A [4 + 3]-cycloaddition reaction of methyl coumalate 12 with an azomethine ylide, formed from imine esters 13 yielded functionalized azepine derivatives 14 (14OL4508). 

The MARDi domino process was also successfully applied to the synthesis of azepanes, azepines, and thiepines. 

Synonyms S -Ethyl azepane-l-carbothioate i -Ethyl hexahydro-l/ -azepine-l-carboth-ioate 5-Ethyl 7V, -hexamethylenethiocarbamate 5-Ethyl perhydroazepine-l-thiocarbox-ylate Felan Higalnate Hydram Jalan Molmate Ordram Ordram 8E Ordram lOG Ordram 15G R 4572 Stauffer R 4572 Sakkimol Yalan Yulan. 

Ampicillin 213 Anabasine 378,433 Anatoxine 539 Aneurine see thiamine Anhalamine 418 Anhalonidine 418 Annular tautomerism 152 Anomeric effect 317 ANRORC mechanism 482 Anthocyanidin 328 Anthocyanin 328 Antihistamines 228 Antipyrine see phenazone Apigenin 340 Arborin 498 Arecoline 433 Aristeromycin 480 Arsabenzene 437 Atebrin 428 ATP 479 Atrazine 512 Atropine 433 Avermectin 318 Aza[10]annulene 550 Aza[14]annulene 550 Aza[18]annulene 550 Azepan-2-one 538 Azepine 533... 

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