A variety of ketonitrones were synthesized in moderate to excellent yields with high chemo-, regio-, and stereoselectivity by using carbonyl-directed addition of N-alkylhydroxylamines to unactivated alkynes under mild conditions. The product diverisity could be controlled by the use of different bases, and EtN(n-Pr)2 could promote the formation of ketonitrones while using EtONa as base led to indanone-derived
Aryne [3 + 2] cycloaddition with N-sulfonylpyridinium imides and in situ generated N-sulfonylisoquinolinium imides: a potential route to pyrido[1,2-b]indazoles and indazolo[3,2-a]isoquinolines
作者:Jingjing Zhao、Pan Li、Chunrui Wu、Hongli Chen、Wenying Ai、Renhong Sun、Hailong Ren、Richard C. Larock、Feng Shi
DOI:10.1039/c2ob06611d
日期:——
The aryne [3 + 2] cycloaddition process with pyridinium imides breaks the aromaticity of the pyridine ring. By equipping the imide nitrogen with a sulfonyl group, the intermediate readily eliminates a sulfinate anion to restore the aromaticity, leading to the formation of pyrido[1,2-b]indazoles. The scope and limitation of this reaction are discussed. As an extension of this chemistry, N-tosylisoquinolinium
与吡啶鎓酰亚胺的芳烃[3 + 2]环加成过程破坏了吡啶环的芳香性。通过在酰亚胺氮上加成磺酰基,该中间体容易消除亚磺酸根阴离子以恢复芳香性,从而导致吡啶并[1,2- b ]吲唑的形成。讨论了该反应的范围和局限性。作为该化学反应的扩展,通过AgOTf催化的6-endo-dig亲电环化反应从N '-(2-炔基亚苄基)-甲苯磺酰肼原位生成的N-甲苯磺酰异喹啉鎓亚胺易于进行芳烃[3 + 2]环加成反应而制得吲哚唑[3,2- a同一锅中的]-异喹啉,为这些潜在的抗癌药提供了高效途径。
Palladium-Catalyzed Cascade Decarboxylative Amination/6-<i>endo-dig</i> Benzannulation of <i>o</i>-Alkynylarylketones with <i>N</i>-Hydroxyamides To Access Diverse 1-Naphthylamine Derivatives
An efficient and practical one-pot strategy to produce highly substituted 1-naphthylamines via sequential palladium-catalyzed decarboxylative amination/intramolecular 6-endo-dig benzannulation reactions has been described. In this reaction, a broad range of electron-rich, electron-neutral, and electron-deficient o-alkynylarylketones react well with N-hydroxyl aryl/alkylamides to give a diversity of
Catalytic Diazosulfonylation of Enynals toward Diazoindenes via Oxidative Radical-Triggered 5-<i>exo</i>-<i>trig</i> Carbocyclizations
作者:Wen-Juan Hao、Yan Du、Dan Wang、Bo Jiang、Qian Gao、Shu-Jiang Tu、Guigen Li
DOI:10.1021/acs.orglett.6b00655
日期:2016.4.15
Catalytic diazosulfonylation of enynals with arylsulfonyl hydrazides has been established by using tert-butyl hydroperoxide (TBHP) as the oxidant with tetrabutylammoniumiodide (TBAI) under a convenient system. The reaction occurred through oxidative radical-triggered 5-exo-trig carbocyclization cascading to afford sulfonylated diazoindenes regioselectively. The new diazosulfonylation reaction features
A new visible‐light photocatalytic arylsulfonylation and bicyclization of C(sp3)‐tethered 1,7‐enynes with sulfinic acids has been developed, delivering functionalized sulfone‐containing benzo[a]fluoren‐5‐ones with generally good yields. This Eosin Y‐catalyzed approach makes use of visible light as a safe and eco‐friendly energy source to drive cascade cyclization reactions, resulting in continuous
已开发出一种新的可见光光催化芳基磺酰化和C(sp 3)系的1,7-烯炔与亚磺酸的双环化,可提供官能化的含砜苯并[ a ]芴-5酮,且收率普遍良好。这种曙红Y催化方法利用可见光作为一种安全且生态友好的能源来驱动级联环化反应,从而导致连续的多个成键事件(包括C–S和C–C键)有效地构建多环连接的烷基芳基砜。