Indium(III) Chloride Mediated Michael Addition of Indoles to Ketene S,S-Acetals: Synthesis of Bis- and Tris-indolylketones
作者:Thokchom Prasanta Singh、Ruhima Khan、Young Ri Noh、Sang-Gyeong Lee、Okram Mukherjee Singh
DOI:10.5012/bkcs.2014.35.10.2950
日期:2014.10.20
A series of bis and tris-indolylketones and meridianin alkaloids are prepared by one pot Michael reaction of indole and ketene S,S-acetals under solvent-free condition using mild Lewis acid $InCl_3$.
一系列的双和三吲哚基酮及经线碱类化合物是通过在无溶剂条件下,利用温和的 Lewis 酸 $InCl_3$,将吲哚与亚硫酸酯酮进行一锅 Michael 反应制备而成的。
Ultrasound-assisted one-pot multicomponent 1,3-dipolar cycloaddition strategy: combinatorial synthesis of spiro-acenaphthylene-<i>S</i>,<i>S</i>-acetal and 2<i>H</i>-pyranone derivatives
2-c]thiazol]-2-one have been achieved through1,3-dipolarcycloaddition. Intermediate azomethine ylides generated in situ from α-amino acids and acenaphthylene-1,2-dione react with α-aroylidine ketenedithioacetal (AKDTA) derivatives to give the target product in excellent yield underultrasoundirradiation. Further, spiro-S,S-acetals are converted to spiro-2H-pyranones by a one-pot cyclization strategy.
新型螺[[-1,3'-吡咯烷] -2-一和螺[ac-1,5'-吡咯并[1,2- c ]噻唑] -2-的文库的立体/区域/化学选择性合成一种是通过1,3-偶极环加成反应实现的。由α-氨基酸和1,2-二酮原位产生的中间体甲亚胺基亚烷基与α-芳基亚乙基酮二硫缩醛(AKDTA)衍生物反应,在超声波照射下以优异的收率得到目标产物。此外,通过一锅环化策略将螺-S,S-乙缩醛转化为螺-2 H-吡喃酮。
Regio- and chemoselective conjugate 1,4-reduction of α-oxoketene dithioacetals with sodium borohydride and sodium cyanoborohydride
Theα-oxoketene dithioacetals are shown to undergo conjugate 1,4-reduction in highly regio- and chemoselective manner with sodium borohydride in acetic acid to afford the corresponding β-oxodithioacetals in good yields. These results have been rationalized according to HSAB principle in terms of 'hard soft affinity inversion' concept. The reduction of with sodium cyanoborohydride also proceeds in 1
One-pot chemo/regio/stereoselective generation of a library of functionalized spiro-oxindoles/pyrrolizines/pyrrolidines from α-aroylidineketene dithioacetals
An efficient chemo/regio/stereoselective synthesis of novel and functionalized spiro-oxindole/pyrrolizine/pyrrolidine scaffolds has been achieved.
一种高效的新型和功能化的螺环氧吲哚/吡咯烷/吡咯啉骨架的化学/位置/立体选择性合成已经实现。
Cyclocondensation of oxoketene dithioacetals with 3-aminopyrazoles: a facile highly regioselective general route to substituted and fused pyrazolo ]pyrimidines
3-amino-5-methylthio-4-phenylpyrazole (1b) withα-oxoketene dithioacetals (2a-j derived from acyclic active methylene ketones affords 5-methylthio-6,7-substituted pyrazolo[1,5-a]pyrimidines (3a-J) exclusively. The reaction was found to be equally successful for the synthesis of 7-styryl,7-(4-aryl-1,3-butadienyl) and 7-(6-aryl-1,3,5-hexatrienyl)pyrazolopyrimidines (7a-f) from the respective enoylketene dithioacetals (6a-f)