在t -BuOK / BEt 3存在下,与亲电二卤化物反应时,未官能化的吲哚可直接转化为3,3'-螺环吲哚和二氢吲哚。这种双CC键形成反应,同时生成一个季螺环中心,通常以高收率进行并且具有良好的官能团耐受性。与现有的脱芳香化螺环化方法相比,不需要制备预官能化的芳香族前体,从而能够一步一步从简单的可商购的芳香族化合物中快速获得有价值的螺环产品。
由N-苯基磺酰基吲哚通过锂化,用D 2 O淬灭并水解来制备2-氘代吲哚。用琥珀酸酐处理2-氘代吲哚格利雅试剂,得到4-(吲哚-3-基)-4-氧代丁酸,氘从2-位部分损失。以相同方式处理的2,3-二氘代吲哚(通过酸催化的2-氘代吲哚的氘代制备)得到吲哚基2-氧代丁酸,其在吲哚基2-位的氘代率为92%。还原为氘代吲哚基丁醇并用叔丁醇钾处理其甲苯对磺酸盐,得到2-氘代-螺[环戊烷-3'-(3 H)吲哚]在2位上氘化了88%。测量了氘代吲哚及其非氘代类似物的酸催化重排动力学,发现拟一级速率常数的比值k H / k D为1.08,表明同位素效应非常小。
A highly enantioselective catalytic Strecker reaction of cyclic (Z)-aldimines
作者:You-Dong Shao、Shi-Kai Tian
DOI:10.1039/c2cc31001e
日期:——
A range of 3H-indoles and 2H-benzo[b][1,4]thiazines smoothly undergo asymmetric Strecker reaction with ethyl cyanoformate in the presence of a Cinchona alkaloid-based thiourea catalyst at 10 °C to give structurally diverse nitrogen-containing heterocycles in good to excellent yields and with excellent ee.
miniaturized and accelerated synthesis for efficient property optimization is a formidable challenge for chemistry in the 21st century as it helps to reduce resources and waste and can deliver products in shorter time frames. Here, we used for the first-time acoustic droplet ejection (ADE) technology and fast quality control to screen efficiency of synthetic reactions on a nanomole scale in an automated
实现高效性能优化的自动化、小型化和加速合成是 21 世纪化学面临的巨大挑战,因为它有助于减少资源和浪费,并可以在更短的时间内交付产品。在这里,我们首次使用声学液滴喷射(ADE)技术和快速质量控制,以自动化和小型化的方式筛选纳摩尔级合成反应的效率。中断的费歇尔吲哚与 Ugi 型反应相结合,产生了几种有吸引力的药物样支架。在 384 孔板中,产生了一组不同的间断 Fischer 吲哚中间体,并通过两步序列与三环乙内酰脲骨架反应。同样,预制的 Fischer 吲哚中间体用于生产多种 Ugi 产品,并将效率与原位方法进行了比较。在制备毫摩尔规模上重新合成了多个反应,显示出从纳米到毫克的可扩展性,从而显示出合成实用性。前所未有的大量建筑被用于快速范围和限制研究(68 种异氰化物,72 种羧酸)。生成的大合成数据的小型化和分析使得能够更深入地探索化学空间,并获得以前不切实际或不可能的知识,例如反应、结构单元和官能团兼容性的快速调查。
Formal Aza‐Diels−Alder Reactions of Spiroindolenines with Electronrich Dienes
serve as imine moiety for formal aza‐Dield‐Alder reactions with electron rich dienes. The reaction delivers tetrahydropyrido[1,2‐a]spiroindolinones as an interesting class of rigid tridimensional polyheterocycles for drug discovery processes. Manipulation of the synthesized compounds encompasses transformation of the functional groups and formation of new carbon–carbon bonds.
螺旋吲哚胺充当亚胺部分,与富电子二烯进行正式的氮杂-狄德-阿德耳反应。该反应将四氢吡啶并[1,2- a ]螺吲哚酮作为一类有趣的刚性三维多杂环化合物用于药物开发过程。合成化合物的操作包括官能团的转化和新的碳-碳键的形成。
2,3-Disubstituted indoles from olefins and hydrazinesvia tandem hydroformylation–Fischer indole synthesis and skeletal rearrangement
作者:Petra Linnepe (née Köhling)、Axel M. Schmidt、Peter Eilbracht
DOI:10.1039/b513364e
日期:——
synthesis of 2,3-disubstituted indoles. After hydroformylation of selected olefins to form alpha-branched aldehydes in a one-pot procedure these are condensed with phenylhydrazine to give hydrazones. Upon acid-promoted [3,3]-sigmatropic rearrangement indolenine intermediates with quaternary centres in the 3-position are formed, which, after selective Wagner-Meerwein-type rearrangement of one of the
Electrophilic substitution in indoles. Part 18. Cyclisation of N-acyltryptamines
作者:Kshetra M. Biswas、Anthony H. Jackson、Mozaina M. Kobaisy、Patrick V. R. Shannon
DOI:10.1039/p19920000461
日期:——
Cyclisation of Nb-acetyltryptamines 8 with trifluoroacetic anhydride, or pentafluoropropionic anhydride, affords spirocyclicindolines of types 14 and 15 in virtually quantitative yields. The mechanism of the reactions involves Cyclisation by ipso-attack at the 3-position of the indole nucleus, to form spirocyclic 3H-indoles 12 and 13, which subsequently undergo addition of the anhydride to the 1,2-double