Convenient Synthetic Protocols for Diverse Functionalized Dihydrobenzofuran-Fused Spiro-indanedione-oxindole Scaffolds
作者:Jing Sun、Xueyan Liu、Qiu Sun、Ying Han、Chao-Guo Yan
DOI:10.1021/acs.joc.3c00887
日期:2023.8.18
1′-cyclopenta[b]benzofuran-2′,3″’-indolines] could be selectively synthesized by using DABCO or DMAP as a base promoter. More importantly, DABCO or DMAP facilitated the annulation reaction of MBH formates of isatins and 2-(o-hydroxybenzylidene)-1,3-indanediones selectively, resulting in spiro[cyclopropa[c]chromene-1,2′-indene]-1′,3′-diones or dispiro[indene-2,1′-cyclopenta[b]benzofuran-2′,3″’-indolines]
通过靛红和 2-(邻羟基亚苄基)-1,3-茚满二酮的 Morita-Baylis-Hillman (MBH) 碳酸酯的碱促进环化反应,方便地合成了多种功能化的二氢苯并呋喃螺环-茚满二酮-羟吲哚支架。以DABCO或DMAP为基础促进剂,可以选择性合成两个非对映体二螺[茚-2,1'-环戊[ b ]苯并呋喃-2',3"'-二氢吲哚]。更重要的是,DABCO或DMAP选择性地促进靛红和2-(邻羟基亚苄基)-1,3-茚二酮的MBH甲酸酯的成环反应,产生螺[环丙[ c ]色烯-1,2'-茚]-1 ',3'-二酮或二螺[茚-2,1'-环戊[ b ]苯并呋喃-2',3"'-二氢吲哚]。此外,与靛红的 MBH 马来酰亚胺进行类似反应,得到二螺[茚-2,5'-苯并呋喃[2',3':1,5]环戊[1,2- c ]吡咯-4',3"'-二氢吲哚] 高产率和高非对映选择性。