Scalable organocatalytic one pot asymmetric Strecker reaction via camphor sulfonyl functionalized crown-ether-tethered calix[4]arene.

In this communication, we designed a highly selective camphor sulfonyl functionalized crown-ether-tethered calix[4]arene-derived organocatalyst for asymmetric Strecker reaction to provide the desired cyano adducts in high yields (∼99.9% yield) and enantioselectivities (up to 99.3% ee). Furthermore, 2 step facile syntheses of the antiplatelet drug (S)-clopidogrel exemplify the potential of this method for the preparation of commercial compounds.

α-Methylbenzylamine Functionalized Crown-Ether-Appended Calix[4]arene Phase Transfer Catalyst for Enantioselective Henry Reaction.

In this letter, we designed a highly selective α-methylbenzylamine functionalized crown-ether-appended calix[4]arene derived phase transfer catalyst for asymmetric nitroaldol reaction to provide the desired nitroaldol adducts in high yields (up to 99 % yield) with good to excellent enantioselectivities (up to 99.8 % ee).

Enantioselective Alkylation of Glycine Imines Using a Cinchona-Functionalized Crown Ether-Strapped Calixarene Phase-Transfer Catalyst.

We report a class of quaternary ammonium Cinchona-functionalized crown ether-strapped calix[4]arene phase-transfer catalysts for the efficient enantioselective α-alkylation of glycine imines. The catalyst exhibits excellent catalytic performance at 0.1 mol % catalytic loading, affording the desired α-alkylated glycinates with 98% yield and 99.9% ee. The catalyst could be recovered and recycled up to 30 test cycles without a significant drop in activity.

Microwave-assisted multicomponent synthesis of antiproliferative 2,4-dimethoxy-tetrahydropyrimido[4,5-b]quinolin-6(7H)-ones.

In this study, we demonstrate a simple, highly efficient, rapid and convenient series of 2,4-dimethoxy-tetrahydropyrimido[4,5-b]quinolin-6(7H)-ones 4a-v. Microwave irradiation facilitates the one-pot multicomponent reaction of different aromatic aldehydes, 6-amino-2,4-dimethoxypyrimidine and dimedone using glacial acetic acid. Metal-free multicomponent synthesis, shorter reaction time, higher product yield, easy product purification without column chromatography and outstanding green credential parameters are the key features of this protocol. We analysed 4a-v against six human tumour cell lines for antiproliferative activity. 4h, 4o, 4q and 4v show good antiproliferative activity with a good in silico ADMET profile. Furthermore, 4h, 4o, 4q and 4v also show drug-likeness properties by obeying drug-like filters.

Client perspectives on perceived barriers to homework adherence in psychotherapy: An exploratory study from India.

We explored perceived barriers to homework adherence in clients receiving individual psychotherapy. Ninety-four adults with at least four individual psychotherapy sessions were recruited from outpatient services of a tertiary hospital in India and assessed on the Barriers to CBT Homework Completion Scale, Homework Compliance Scale, and Clinical Global Impressions scale. More than one-fourth completed some portion of the homework. Participants reported a high level of overall perceived barriers to homework, with more task-and-patient related factors. Higher perceived barriers were associated with lower adherence. Findings highlight the importance of understanding perceived barriers to homework adherence and addressing them systematically.

Experimental and computational studies on the Cinchona anchored calixarene catalysed asymmetric Michael addition reaction.

Lower-rim Cinchona anchored calix[4]arene cationic catalysts were developed for asymmetric Michael addition of acetylacetone to ß-nitrostyrenes. The desired Michael adducts were formed with high yields and enantioselectivities. Density functional theory investigations throw light on the catalyst-substrate interaction and the reaction mechanism.

Calix[4]amido crown functionalized visible sensors for cyanide and iodide anions.

This study comprises the design and development of calix[4] arene-amido-based ionophores by varying structural stringency and steric hindrance at the lower rim to probe the anion sensing properties. The ionophores are prepared, purified, and characterized using various analytical techniques. The molecular structure of the most active ionophore I is established by single-crystal X-ray characterisation. Out of various anions investigated, iodide and cyanide show the highest sensitivity towards the ionophores investigated. Both anions are sensitive enough to give a visibly distinct color change. The binding properties of the ionophores are established with 1H & 127I NMR, fluorescence, and UV-vis spectroscopy, revealing that three ionophores strongly interact with CN- and I-. The binding constants are calculated via Benesi-Hildebrand plots using absorption data. The time-dependent 1H NMR revealed strong hydrogen bonding between the OH and NH groups of the ionophore and cyanide anion. The 127I NMR shows the highest 27.6 ppm shift after 6 h for ionophore I. The crystal structure revealed hydrogen bonding of N-H protons of the amide pendulum and phenolic oxygen of the calix rim. The Job's plot depicted the possibility of a 1 : 1 complex of ionophores with both anions.