College of Chemistry & Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
Org Biomol Chem. 2019 Apr 17;17(16):3978-3983. doi: 10.1039/c9ob00166b.
The three-component reaction of 1,3-indanedione and N-alkylisatins with two molecular N-phenacylpyridinium salts in dry acetonitrile in the presence of triethylamine resulted in unique functionalized spiro[indoline-3,4'-naphtho[1,2-b]furan] derivatives in good yields, which were successfully converted to spiro[indoline-3,2'-naphthalen]-4'-yl acetate derivatives by acylation with acetyl chloride in methylene dichloride and alkoxy-substituted spiro[benzo[h]chromene-5,3'-indolines] by acid-catalyzed etherification reaction in alcohol. The reaction mechanism involved the sequential cycloaddition of the in situ-generated pyridinium ylide to dipolarophilic enone, ring-opening of 1,3-indanedione, and selective annulation.
1,3-茚二酮和 N-烷基靛红与两个分子的 N-苯甲酰基吡啶翁盐在三乙胺存在下在干燥乙腈中的三组分反应以良好的收率得到了独特的功能化螺[吲哚啉-3,4'-萘[1,2-b]呋喃]衍生物，这些衍生物可通过乙酰氯在二氯甲烷中的酰化成功转化为螺[吲哚啉-3,2'-萘]-4'-基乙酸酯衍生物，也可通过酸催化的醇中的醚化反应转化为烷氧基取代的螺[苯并[h]色烯-5,3'-吲哚啉]。反应机理涉及原位生成的吡啶翁盐的顺序环加成到偶极亲电烯酮，1,3-茚二酮的开环和选择性环合。
