Faculty of Pharmaceutical Sciences, Hiroshima International University, 5-1-1 Hirokoshingai, Kure, Hiroshima 737-0112, Japan.
J Org Chem. 2010 Nov 19;75(22):7615-25. doi: 10.1021/jo101347f. Epub 2010 Oct 21.
By using platinum(II) chloride as a Lewis acid catalyst, concise and efficient syntheses of indole carbamates, 1,2-dihydroisoquinoline carbamates, macrocyclic indole carbamates, indole ureas, and indole phosphoranes have been achieved via tandem Hofmann-type rearrangement of 2-alkynylbenzamides and 2-alkynylbenzylamides, nucleophilic addition of alcohols and amines to the isocyanate intermediates, and intramolecular aminocyclization of the thus-formed carbamates and ureas to 2-alkynyl functions. A variety of nucleophiles such as alcohols, amines, and stable Wittig reagents could be introduced to the highly electrophilic carbon of the isocyanate intermediates derived from amides. We observed enhancement of the reaction rates when the reactions were run under microwave irradiation.
通过使用氯化铂（II）作为路易斯酸催化剂，通过 2-炔基苯甲酰胺和 2-炔基苄胺的串联 Hoffmann 型重排、醇和胺对异氰酸酯中间体的亲核加成以及由此形成的氨基甲酸酯和脲的分子内氨基环化反应，实现了吲哚氨基甲酸酯、1,2-二氢异喹啉氨基甲酸酯、大环吲哚氨基甲酸酯、吲哚脲和吲哚膦的简洁高效合成。各种亲核试剂，如醇、胺和稳定的 Wittig 试剂，可以引入酰胺衍生的异氰酸酯中间体的高反应性碳上。当反应在微波辐射下进行时，我们观察到反应速率提高。
