作者:Mukesh Kumar、Pankaj Chauhan、Stephen J. Bailey、Ehsan Jafari、Carolina von Essen、Kari Rissanen、Dieter Enders
DOI:10.1021/acs.orglett.8b00175
日期:2018.2.16
An efficient and highly stereoselective one-pot, four-component synthesis of functionalized tricyclic chromanes has been achieved through an organocatalyzed quadruple dominoreaction. The reaction sequence involves an oxa-Michael/Michael/Michael/aldol condensation between alcohols, 2 equiv of acrolein, and nitrochromenes to generate the pharmaceutically important tricyclic chromanes bearing three contiguous
通过有机催化的四重多米诺反应,已实现了高效且高度立体选择性的一锅四组分官能化三环苯并吡喃的合成。反应顺序包括在醇,2当量的丙烯醛和硝基色酮之间进行oxa-Michael / Michael / Michael / aldol缩合反应,以产生药学上重要的三环苯并三环苯并烷,其中包括三个连续的立体异构中心,包括手性四取代碳中心,具有良好的多米诺产量(30– 70%)和出色的非对映选择性和对映选择性(> 20:1 dr和> 99%ee)。
Enantioselective cascade double Michael addition of 3-nitro-2H-chromenes and acyclic enones: efficient synthesis of functionalized tricyclic chroman derivatives
作者:Jun-Hua Li、Da-Ming Du
DOI:10.1039/c5ob01211b
日期:——
tetrahydro-6H-benzo[c]chromenes and their derivatives has been developed. The corresponding products were obtained by the cascade double Michael addition of 3-nitro-2H-chromenes and their derivatives with α,β-unsaturated ketones catalyzed by a combination of a quinine-derivedprimaryamine and benzoic acid. Through this methodology, the desired products could be obtained in moderate to good yields (up to
已经开发出用于不对称构造对映体富集的四氢-6 H-苯并[ c ]色烯及其衍生物的有效方案。相应的产物通过将3-硝基-2 H-色酮及其衍生物与奎宁衍生的伯胺和苯甲酸的组合催化的α,β-不饱和酮进行级联双迈克尔加成而获得。通过这种方法,可以以中等至良好的收率(高达90%),具有优异的非对映选择性(高达> 25:1 dr)和中等至优异的对映选择性(高达95%ee)获得所需的产物。
Enantioselective synthesis of chiral heterocycles containing both chroman and pyrazolone derivatives catalysed by a chiral squaramide
作者:Jun-Hua Li、Da-Ming Du
DOI:10.1039/c4ob02653e
日期:——
An efficient chiral squaramide-catalysed enantioselective Michael addition of pyrazolin-5-ones to 3-nitro-2H-chromenes afforded chiral heterocycles containing both chroman and pyrazolone derivatives in high to excellent yields (up to 98%) with high enantioselectivities (up to 96%) under very low catalyst loading (0.2 mol%).
Asymmetric Friedel–Crafts alkylation of indoles with 3-nitro-2H-chromenes catalyzed by diphenylamine-linked bis(oxazoline) and bis(thiazoline) Zn(II) complexes
作者:Yang Jia、Wen Yang、Da-Ming Du
DOI:10.1039/c2ob25360g
日期:——
enantioselective Friedel–Crafts alkylation of indoles with 3-nitro-2H-chromenes catalyzed by diphenylamine-linked bis(oxazoline) and bis(thiazoline) Zn(II) complexes has been developed. This asymmetric Friedel–Crafts alkylation led to medicinally privileged indolyl(nitro)chromans in good yields with high enantioselectivities (up to 95% ee) and diastereoselectivities under mild reaction conditions.
Phosphane‐Catalyzed [3+2] Annulation of Allenoates with 3‐Nitro‐2
<i>H</i>
‐chromenes: Synthesis of Tetrahydrocyclopenta[
<i>c</i>
]chromenes
作者:Maria I. L. Soares、Clara S. B. Gomes、Sandra C. C. Nunes、Alberto A. C. C. Pais、Teresa M. V. D. Pinho e Melo
DOI:10.1002/ejoc.201900564
日期:2019.9
The phosphane‐catalyzed [3+2] annulations of allenoates with 3‐nitrochromenes are described allowing the synthesis of 3a‐nitro‐tetrahydrocyclopenta[c]chromenes with high stereo‐ and regioselectivity. Quantum chemical calculations corroborate the experimental results. 3a‐Nitro‐tetrahydrocyclopenta[c]chromenes are converted into the corresponding amines by HSiCl3‐mediated reduction.
描述了用3-硝基色烯进行膦酸酯催化的烯丙酸酯的[3 + 2]环,可以合成具有高立体选择性和区域选择性的3a-硝基-四氢环戊五烯[ c ]色烯。量子化学计算证实了实验结果。通过HSiCl 3介导的还原作用,可将3a-硝基-四氢环戊五烯[ c ]铬酮转化为相应的胺。