カサシマ ヨシオ
YOSHIO KASASHIMA
笠嶋 義夫 所属 千葉工業大学 創造工学部 教育センター(創造工学部) 職種 教授 |
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言語種別 | 英語 |
発行・発表の年月 | 2018/10 |
形態種別 | 学術雑誌 |
査読 | 査読あり |
標題 | Umpolung cyclization reaction of N-cinnamoylthioureas in the presence of DBU |
執筆形態 | 共著 |
掲載誌名 | Organic & Biomolecular Chemistry |
掲載区分 | 国外 |
出版社・発行元 | Royal Society of Chemistry |
巻・号・頁 | 16,pp.7910-7919 |
著者・共著者 | Rei Saito, Naohiro Uemura, Hiroki Ishikawa, Akina Magara, Yasushi Yoshida, Takashi Mino, Yoshio Kasashima and Masami Sakamoto |
概要 | AbstractA novel regioselective cyclization reaction of N-cinnamoylthioureas leading to six- or five-membered heterocyclic compounds was developed. N-Cinnamoylthioureas in the presence of trifluoroacetic acid (TFA) underwent the well-established intramolecular cycloaddition reaction to give 2-imino-2,3,5,6-tetrahydro-4H-1,3-thiazin-4-ones in good yields. On the other hand, the reaction with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) proceeded in an unprecedented umpolung cyclization fashion to afford five-membered 2-imino-1,3-thiazolidin-4-ones and/or 2-thioxoimidazolidine-4-ones. The reaction was considered to occur via a cycloadduct of DBU with the cinnamoyl moiety followed by intramolecular attack of the thiourea group. |
DOI | 10.1039/C8OB02066C |
ISSN | 1477-0520 |