Synthesis of α1-oxindole-α-hydroxyphosphonates under catalyst-free conditions using polyethylene glycol (PEG-400) as an efficient and recyclable reaction medium

A colorimetric and fluorescent dual probe for palladium in aqueous medium and live cell imaging

A colorimetric and fluorescent dual probe for palladium species was rationally developed by combining the resorufin fluorophore with allyl chloroformate.

Catalyst-free synthesis of α1-oxindole-α-hydroxyphosphonates via phospha-aldol reaction of isatins employing N-heterocyclic phosphine (NHP)-thiourea

A catalyst-free phospha-aldol reaction of isatins with NHP-thiourea has been developed and the critical role of the Brønsted acid in this transformation is unveiled.

Three-component, one-pot synthesis of benzo[6,7]cyclohepta[1,2-b]pyridine derivatives under catalyst free conditions and evaluation of their anti-inflammatory activity

An efficient three-component protocol is described for the synthesis of benzo[6,7]cyclohepta[1,2-b]pyridine derivatives using β-chloroacroleins, 1,3-dicarbonyls and ammonium acetate under catalyst free conditions by using ethanol as reaction media. The mild reaction conditions, operational simplicity and high yields are the advantages of this protocol and the broad scope of this one-pot reaction makes this procedure promising for practical usages. All the final compounds were screened for anti-inflammatory activity. Among the compounds tested, the compounds 5a, 5b, 5c, 5d, 5f, and 5k exhibited significant inhibition of IL-1β and MCP-1 secretion as a measure of anti-inflammatory activity.

Highly selective and sensitive fluorescence chemosensor for the detection of palladium species based on Tsuji-Trost reaction

A new chemosensor 7-nitro-2,1,3-benzoxadiazole-4-allyl-N-(thiophen-2-ylmethyl)carbamate (NBDTC) was synthesized and utilized for palladium detection based on the Tsuji-Trost reaction. NBDTC displayed specific and ratiometric fluorescent responses toward palladium species. The chemosensor showed more than 50-fold enhancement in fluorescence intensity with the presence of PEG400 and palladium because NBDTC can be transformed to NBDT under palladium-catalyzing Tsuji-Trost reaction. NBDTC displayed high selectivity and sensitivity for palladium species with the detection limit of 1.13×10(-9) M.

Isatin derivatives in reactions with phosphorus(III-V) compounds

In this review we generalize and analyze information about reactions between isatin and three-, four-, and five-coordinate phosphorus compounds, published between 1966 and 2014.

Polyethylene glycol (PEG-400): an efficient and recyclable reaction medium for the synthesis of pyrazolo[3,4-b]pyridin-6(7H)-one derivatives

A mild and efficient synthesis of pyrazolo[3,4-b]pyridine-6(7H)-one derivatives via a three-component reaction of an aldehyde, Meldrum's acid and 3-methyl-1H-pyrazol-5-amine using recyclable polyethylene glycol (PEG)-400 as a reaction medium is described. This method has the advantages of accessible starting materials, good yields, mild reaction conditions and begin environmentally friendly.