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
Catalytic enantioselective alkylation of heteroaromatic compounds using alkylidene malonates
作者:Wei Zhuang、Tore Hansen、Karl Anker Jørgensen
DOI:10.1039/b009008p
日期:——
A catalytic enantioselective alkylation of heteroaromatic
compounds using alkylidene malonates has been developed; the reaction
proceeds for different heteroaromatic compounds with alkylidene malonates
in high yield and enantiomeric excess.