Imidazoline is an important class of compounds found in numerous natural and pharmaceutical products. The compounds are also used as an intermediate in the synthesis of organic molecules. Moreover, chiral imidazolines are widely utilized as organocatalysts to synthesize various natural and synthetic organic compounds. In the past decade, there was an increase in interest in developing new methods to synthesize these imidazoline analogs. Both modification of the previously established methods and the development of new methods are carried out significantly. This review article highlights the progress of the synthesis of imidazoline scaffolds in the last few years (2009-present). The review also described the proposed mechanism illustrated in many of the reports.

This work describes an extended version of the Corey–Chaykovsky reaction to access oxazolines using sulfur ylides and stable precursors of acyl imines. The reaction proceeds through a mixture of aziridines and oxazolines, which provides the trans-oxazolines following in situ Heine-type aziridine ring expansion upon treatment with BF3·OEt2. Following the same one-pot procedure, amidine imides react with the sulfur ylides to provide imidazolines.

Here, we report the first synthesis of 2,3-disubstituted quinolines from anilines and aromatic or aliphatic epoxides. This reaction utilizes Sc­(OTf)3 as a Lewis acid and TEMPO as an oxygen scavenger. A wide variety of highly substituted quinolines were obtained with moderate to excellent yields (up to 96%).

The methanolic extracts of bark, leaf and seed of E. rheedii and their Kupchan partitionates were investigated for in vitro cytotoxic, antioxidant, thrombolytic, membrane stabilizing and antimicrobial activities. In the brine shrimp lethality bioassay, the chloroform soluble extractive from seed showed significant cytotoxicity (LC50 = 1.95 µg/ml and LC90 = 3×10 -4 µg/ml) as compared to vincristine sulfate (LC50 = 0.45 µg/ml and LC90 = 9×10 -6 µg/ml). Antioxidant activity was screened using DPPH assay and ethyl acetate soluble partitionate of bark revealed the highest free radical scavenging activity with IC50 values of 33.68 μg/ml as compared to standard, ascorbic acid (IC50 4.05 μg/ml) and butylated hydroxyl toluene (IC50 27.50 μg/ml). Significant membrane stabilizing activities were observed for aqueous and ethyl acetate soluble fractions of bark in hypotonic solution-induced haemolysis (94.94%) and in heat induced condition (97.39%), respectively. No significant antimicrobial and thrombolytic activities were observed for any extractive from this plant. Chemical investigation of the seed extract of E. rheedii provided entadamide A (1) for the first time from this plant, which was isolated previously from E. phaseoloides. This is the also the first report of the bioactivities of this plant.

Here, we report the synthesis of 3,4-disubstituted 1Hpyrazoles and 3,5-disubstituted pyridines from the reaction of epoxides with hydrazine and ammonia, respectively. Both reactions utilize Sc(OTf) 3 as a Lewis acid. The pyrazole synthesis utilizes N-bromosuccinimide to convert the intermediate pyrazolines to the pyrazoles, whereas the pyridine synthesis utilizes FeCl 3 as a cocatalyst.