The ultra high pressure conjugate addition of indoles to electron-deficient olefins
作者:Paul Harrington、Michael A Kerr
DOI:10.1139/v98-158
日期:1998.9.1
The addition of indole and methyl indole at both high and ambient pressures to a series of Michael acceptors under the influence of ytterbium triflate was investigated. Under ambient pressure the more reactive and less stericallyhindered electrophiles gave the expected 3-alkylated indoles in good to excellent yields. The more problematic Michael acceptors were subjected to pressures of 13 kbar. In
研究了在三氟甲磺酸镱的影响下,在高压和环境压力下将吲哚和甲基吲哚添加到一系列迈克尔受体中。在环境压力下,反应性更强且空间位阻较小的亲电子试剂以良好至极好的产率得到预期的 3-烷基化吲哚。问题较多的迈克尔受体承受 13 kbar 的压力。在所有情况下,都观察到反应时间的显着减少和产率的显着提高。在涉及 3-methylcyclohex-2-en-1-one 的情况下,形成了副产物并通过单晶 X 射线衍射表征。α、β-不饱和酮的产率最高。Enals 倾向于聚合,而 enoates 被证明太不活泼了。
Deep eutectic solvent: An efficient and green catalyst for the three-component condensation of indoles, aromatic aldehydes, and activated methylene compounds
The deep eutectic solvent-catalyzed multicomponent reaction of aldehydes, indoles, and activated methylene compounds under sonication has been developed. The method proceeded well for a wide scope of substrates under mild condition to afford 3-substituted indoles in moderate to good yields. Interestingly, no additives or solvents are used for the protocol. Moreover, the deep eutectic solvent (zinc
Mechanochemical Copper‐Catalyzed Asymmetric Michael‐Type Friedel–Crafts Alkylation of Indoles with Arylidene Malonates
作者:Plamena Staleva、José G. Hernández、Carsten Bolm
DOI:10.1002/chem.201901826
日期:2019.7.11
asymmetric Michael‐type Friedel–Crafts alkylation of indoles with arylidene malonates was developed. The reaction proceeds under ambient atmosphere using a chiral bis(oxazoline)copper catalyst in a mixer mill. Under these reaction conditions nineteen 3‐substituted indolederivatives were synthesized in good to excellent yields (up to 98 %), and with good enantioselectivities (up to 91:9 e.r.) after short milling
efficient catalytic asymmetric Friedel–Crafts alkylation of indoles with alkylidene malonates has been developed by using a chiral N,N′‐dioxide–Sc(OTf)3 complex as the catalyst (see scheme). Some opticallyactive intermediates containing the indole skeleton have been synthesized, such as indolepropionic acid, tryptamines, and β‐carbolines. The coordination between the scandium atom and the chiral N,N′‐dioxide
bis(oxazoline) ligands, especially azabis(oxazolines), can catalyze the copper-catalyzed addition of indoles to benzylidenemalonates in up to >99% ee, provided that excess of chiral ligand is avoided. The paradigm followed in many asymmetric catalyses that an excess of chiral ligand with respect to the metal should improve enantioselectivity because a background reaction by free metal is suppressed