A rational eco-compatible design strategy for regio- and diastereoselective synthesis of novel dispiropyrrolidine/thiapyrrolizidine hybrids

An eco-compatible synthesis of novel spiro[acenaphthylene-1,2′[1,3]-thiazolidine]-2,4′(1H)-diones using thiamine hydrochloride as efficient catalyst in aqueous medium

“…Hence, inspired by these findings and in continuation of our ongoing work to develop environmentally benign methodologies [54][55][56][57][58][59][60][61] for the synthesis of biologically useful heterocycles, we have investigated a threecomponent protocol for the synthesis of drug-like spiro[acenaphthylene-1,2 0 [1,3]-thiazolidine]-2,4 0 (1H)-diones from the multi-component reaction of acenapthaquinone, substituted anilines, and a-mercaptoacetic acid in good yield using thiamine hydrochloride as a green, inexpensive, and reusable catalyst in aqueous medium. The present method is more convenient and efficient because it obviates the azeotropical removal of water and use of carcinogenic solvents as well as dehydrating agents.…”

Green Protocols in Heterocycle Syntheses via 1,3-Dipolar Cycloadditions

“…The use of 2,2,2-trifluoroethanol as a recoverable greener solvent was explored by Dandia, to obtain a series of novel efficiently regio- and stereoselective dispiropyrrolidinyl/thiapyrrolizidinyl hybrid molecules via the 1,3-dipolar cycloaddition of a benzo[1,4]oxazine-derived dipolarophile, isatin and sarcosine/1,3-thiazolane-4-carboxylic acid (Dandia et al, 2015). The dipolarophile was synthesized under catalyst-free conditions from o-aminophenol and dimethyl acetylene dicarboxylate (DMAD) in good yields.…”

1,3‐Dipolar Cycloadditions of Stabilized Azomethine Ylides and Electrophilic Alkenes Mediated by a Recyclable TSIL·AgOAc Catalyst

“…For example, heterogeneous graphene oxide, [4] zinc oxide nanoparticles, [5] heterogeneous silver nanoparticle, [6] bentonite, [7] were used as a recyclable catalyst. 2,2,2-Trifluoroethanol as a modern green solvent, [15] PEG-400, [16] ethyl lactate as a bio-based green solvent, [17] and ethanol, [18] were also considered new green alternatives. Sequential thermal (MW) [3+2] cycloaddition involving imino esters generated in situ was also efficient in a multicomponent fashion.…”

“…[11][12][13] Even reactions where products were isolated in good yield by simple filtration [14] can be considered a good green approach. 2,2,2-Trifluoroethanol as a modern green solvent, [15] PEG-400, [16] ethyl lactate as a bio-based green solvent, [17] and ethanol, [18] were also considered new green alternatives. green methodology.…”