160 research outputs found
An efficient modification of the Hofmann rearrangement : synthesis of methyl carbamates
—A series of methyl carbamates was synthesized using NaOCl as an oxidant in the presence of KF/Al 2O 3/MeOH at reflux
in excellent yields
AlCl3,6H2O/KI/H2O/CH3CN : a new alternate system for dehydration of oximes and amides in hydrated media
Dehydration of oximes and amides to nitriles was
carried out using the AlCl3â6H2O/KI/H2O/CH3CN system. It
produced isoquinoline derivatives 8a-c (Bischler Naperialski
reaction) when reacted with amides 7a-c in hydrated
media. Also, the keto oximes produced anilides (Beckmann
rearrangement) with the system under the same reaction
conditions
Practical, Ecofriendly, and Chemoselective Method for the Synthesis of 2-Aryl-1-arylmethyl- 1H-benzimidazoles Using Amberlite IR-120 as a Reusable Heterogeneous Catalyst in Aqueous Media
A simple, efficient, and environmentally benign method has been
developed for the exclusive formation of biologically significant 2-aryl-1-
arylmethyl-1H-benzimidazoles under the heterogeneous catalysis of Amberlite
IR-120 in aqueous media in excellent yields. The catalyst is recyclable without loss
of activity
KF/Al2O3 mediated 1,3-dipolar cycloaddition of azomethine ylides: a novel and convenient procedure for the synthesis of highly substituted pyrrolidines
—The regio- and diastereoselective synthesis of pyrrolidine derivatives through 1,3-dipolar cycloaddition of an azomethine
ylide and dipolarophile mediated by KF/Al 2O 3, a versatile solid supported reagent, is reported. KF/Al 2O 3 is sufficiently basic such
thatitcandeprotonatea-iminoesterstogenerateazomethineylidesanditalsofunctionsasasolidsupportedcatalystleadingtothe
cycloadduct rather than the Michael adduct.
2007 Elsevier Ltd. All rights reserved
AN EFFICIENT SYSTEM FOR DEPROTECTION OF OXIMES AND IMINES TO CARBONYLS UNDER NEUTRAL CONDITIONS IN WATER
A simple, green and one-pot four-component synthesis of 1,4-dihydropyridines and their aromatization
A simple, green and cost-effective protocol was achieved for the solvent free synthesis of 1,4-dihydropyridines catalyzed by
AlCl3 Æ 6H2O as a mild and effective catalyst at 60 �C in high yields. 1,4-Dihydropyridines thus formed were aromatized to pyridines
by in situ generation of HOCl employing AlCl3 Æ 6H2O/H2O2/H2O/EtOH as an excellent reagent system under domestic microwave irradiation
(MWI). Both the synthesis and oxidation steps were efficiently accomplished in one-pot four-component fashion following the
same protoco
An efficient and one-pot synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles catalyzed by InCl3·3H2O
InCl3�3H2O was found to be a mild and effective catalyst for the efficient, one-pot, three component synthesis of 2,4,5-trisubstituted
imidazoles at room temperature. Moreover, the utility of this protocol was further explored conveniently for the one-pot, four
component synthesis of 1,2,4,5-tetrasubstituted imidazoles in high yields
DMSO/N2H4.H2O/I2/H2O/CH3CN : A new system for selective oxidation of alcohols in hydrated media
A new alternative system for the oxidation of
secondaryalcoholstoketoneswithDMSO/N2H4‚H2O/I2/H2O/
CH3CN in hydrated media has been developed. The system
also selectively oxidizes the secondary alcoholic groups to
the corresponding ketones in the presence of primary
alcoholic groups present within the same molecule in moderate
to very good yields at reflux temperature
Rhodium(I) carbonyl complexes of triphenylphosphine chalcogenides and their catalytic activity
Rhodium(I) carbonyl complexes [Rh(CO)2ClL] where L = Ph3PO, Ph3PS and Ph3PSe, were synthesized and
characterized by elemental analysis, i.r. and by 1H-, 13C- and 31P-n.m.r. spectroscopy. The m(CO) band frequencies
in the complexes follow the order: Ph3PO > Ph3PS > Ph3PSe, in keeping with the hard/soft nature of the
interactions. The complexes undergo oxidative additions with electrophiles such as MeI, PhCH2Cl and I2 to give,
e.g. [Rh(CO)(COMe)ClIL] which react with PPh3 to give trans-[Rh(CO)Cl(PPh3)2]. The catalytic activity of the
[Rh(CO)2ClL] complexes in carbonylation of MeOH is higher than that of the well-known [Rh(CO)2I2]ÿ specie
- …