The
first metal-catalyzed double aryl C(sp2)–H
bond activation of antipyrine and alkyne annulation reaction is reported.
This Ru(II)-catalyzed reaction was accomplished in the presence of
20 mol % phosphine ligand tricyclohexylphosphine tetrafluoroborate
to afford indolo[2,1-a]isoquinolines that are very
important compounds because of their bioactivity and interesting optical
properties.
An
unprecedented Pd(II)-catalyzed decarbonylative C–H/C–C
activation and annulation reaction, which proceeds via intramolecular
cyclization, is reported. This reaction of hydroxynaphthoquinones
with disubstituted alkynes provides good yields of substituted alkylidene
phthalides, which are the key intermediates for the synthesis of bioactive
natural products.
An efficient catalyst-free, one-pot multicomponent reaction has been developed for the synthesis of pyrimidine functionalized pyrrolo-annelated derivatives. The method offers easy and column free separation, mild reaction conditions and high yields.
A simple and efficient l-proline-catalysed synthesis of spiro(isoxazolo[5,4-b]pyridine-5,5′-pyrimidine) derivatives in water has been accomplished through a pseudo five-component one-pot domino aza-Diels–Alder reaction involving 3-amino crotanonitrile, hydroxylamine hydrochloride, aromatic aldehydes and barbituric acids. The main advantages of the present method are mild reaction conditions, modest purification process involving no chromatographic techniques and high yields. The protocol is a good alternative to prepare spiro derivatives with readily available starting materials, which makes the method highly attractive.
A new directing group assisted method for the synthesis of aryl esters is described. In this Cu(ii)-mediated reaction, 2-formylphenols and 2-acetylphenols are easily converted into aryl esters via treatment with a new aroylating agent 2-bromoacetophenone. In addition, a new external bromine free method for the synthesis of important synthons 2,2-dibromoacetophenones from 2-bromoacetophenones is described.
An ew methodf or the annulation reactiono f salicylaldehydes with propargyl bromidei sd escribed. This Ru II -catalyzed annulation reactionp rovides2 -methylchromones, which are as ubstructure of many biologically active natural products.T he annulation reactionc ould be further extendedt ot he synthesis of 2-methylfuran-fused compounds.
Spironaphthoquinolines can be obtained with good yields in an ultrasoundmediated pseudo one-pot condition from easily available starting materials. The association of the process with 'atom-economy' and 'procedural simplicity' makes it an attractive protocol to synthesize desired compounds.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.