Structural reorganization of (allyl-, benzyl-, and propargylsulfanyl)-substituted 2-aza-1,3,5-trienes in t-BuOK/THF/DMSO: access to rare functionalized 2-thiazolines

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• 作者：Nina A. Nedolya ; ^{nina@irioch.irk.ru" class="auth_mail} ; Ol&rsquo ; ga A. Tarasova ; Alexander I. Albanov ; Boris A. Trofimov
• 关键词：Methoxyallene ; Isothiocyanates ; 2-Aza-1 ; 3 ; 5-trienes ; Deprotonation ; 2-Thiazolines ; Azepines
• 刊名：Tetrahedron Letters
• 出版年：9 April, 2014
• 年：2014
• 卷：55
• 期：15
• 页码：2495-2498
• 全文大小：855 K

文摘

Treatment of (allyl-, benzyl-, and propargylsulfanyl)-substituted 2-aza-1,3,5-trienes, which are readily accessible from lithiated methoxyallene, isopropyl isothiocyanate, and allyl, benzyl, or propargyl bromide, respectively, with t-BuOK in THF/DMSO resulted in the unexpected formation of 2-thiazoline derivatives along with seven-membered azaheterocycles [in the case of (allyl- and benzylsulfanyl)-substituted 2-aza-1,3,5-trienes]. An unprecedented structural reorganization of the azatrienes into 2-thiazolines presumably occurs via 伪-deprotonation of the substituents at the sulfur atom followed by intramolecular [1,5]-cyclization. Deprotonation of the ketimine fragment of the same molecule followed by [1,7]-electrocyclization resulted in azepine ring formation.