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.

A facile method has been developed for the synthesis of a novel indoline spiropyran derivatives via three‐component, catalyst‐free domino Knoevenagel/oxa‐Diels‐Alder (DKODA) reaction strategy at room temperature. The key step of the methodology is the in situ generation of oxa diene from Knoevenagel condensation of 4‐hydroxycoumarin 1 and aldehyde 2 undergoes oxa‐Diels‐Alder cyclization with dienophile 1,3,3‐trimethyl‐2‐methyleneindoline 3 to give the indoline spiropyran derivative 4.