@article { ISI:000254443900045, title = {Efficient synthesis of 1,8-dioxo-octahydro-xanthene derivatives promoted by a room temperature ionic liquid at ambient conditions under ultrasound irradiation}, journal = {Ultrasonics Sonochemistry}, volume = {15}, number = {4}, year = {2008}, month = {APR}, pages = {548-553}, publisher = {ELSEVIER SCIENCE BV}, type = {Article}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

The condensation reaction involving an aldehyde and diketone was efficiently promoted by the Ionic liquid, [Hbim]BF(4) (IL) as a reaction medium with methanol as co-solvent at ambient temperature under ultrasonic irradiation to afford the corresponding 1,8-dioxo-octahydroxantliene (xanthene) derivatives in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under ambient temperature without the requirement of ally added catalyst. The reaction times and yields are compared with p-TSA catalyzed synthesis of xanthenes under thermal conditions, which is also reported for the first time under our reaction conditions. (c) 2007 Elsevier B.V. All rights reserved.

}, keywords = {aldehydes, ambient conditions, Bronsted acidity, dimedone, Ionic liquid, Ultrasound, Xanthenes}, issn = {1350-4177}, doi = {10.1016/j.ultsonch.2007.06.001}, author = {Venkatesan, K. and Pujari, Suresh S. and Lahoti, Rajgopal J. and Srinivasan, K. V.} } @article {46318, title = {Dimedone-based rigid organic scaffold for organizing symmetrical helical peptide chains.}, journal = {ChemistrySelect}, volume = {4}, year = {2019}, month = {OCT }, pages = {11518-11522}, type = {Article}, abstract = {

We describe herein design, synthesis and conformational investigations of polypeptides attached on a rigid dimedone template. Two identical peptide chains are attached on a single carbon containing dimedone as a scaffold. Dimedone assists in controlling the secondary interactions through strong intramolecular helical C-12 and C-15 membered bifurcated hydrogen bonding on both the peptide chains along with propagating the helical architecture of the peptide chains attached. There exists a C-6 hydrogen bonding for the single stranded peptides attached to dimedone. Extensive structural investigations involving single crystal X-ray diffraction, solution-state NMR and CD studies of oligopeptides have been undertaken.

}, keywords = {dimedone, Helical, hydrogen bonding, Peptides, template}, issn = {2365-6549}, doi = {10.1002/slct.201903087}, author = {Madica, Krishnaprasad and Lakshmi, Jerripothula K. and Madhu, Suresh and Nadimpally, Krishna Chaitanya and Gonnade, Rajesh and Jagadeesh, Bharatam and Sanjayan, Gangadhar J.} } @article {48294, title = {Efficient and convenient heterogeneous Cu/MCM-41 catalyst for the synthesis of 7,10,11,12-tetrahydrobenzo[c]acridin-8(9H)-one derivatives}, journal = {Research on Chemical Intermediates}, volume = {49}, year = {2023}, month = {APR}, pages = {1581-1600}, type = {Article}, abstract = {

An efficient and convenient method for synthesis of 7,10,11,12-tetrahydrobenzo[c]acridin-8(9H)-one derivatives using Cu/MCM-41 (20 mg) as heterogeneous catalyst. The advantages have an excellent product yield within a short time and easy work-up procedure, and the products have directly recrystallized from hot methanol with cost-effective catalyst. One-pot three-component reaction from aromatic aldehydes, cyclic 1,3-dicarbonyl compounds, and 1-naphthyl amine has been carried under ethanol as a solvent with reflux condition. Moreover, the catalyst can be recovered conveniently and reused efficiently, and recyclable. [GRAPHICS] .

}, keywords = {Benzo[c]acridine, dimedone, Heterogeneous Cu/MCM-41 catalyst, Multicomponent one-pot reaction}, issn = {0922-6168}, doi = {10.1007/s11164-023-04962-3}, author = {Dhengale, Shankar D. and Bhosale, Tanaji R. and Shinde, Sachin B. and Rode, Chandrashekhar V. and Kolekar, Govind B. and Anbhule, Prashant V.} }