The Erlenmeyer synthesis with a thioazlactone

2-Phenylthiazolin-5-one (2b) was generated in situ and condensed with various aldehydes in CH2Cl2 (r.t./20 min.), to obtain the corresponding 4-alkylidene or arylidene products in good yields (68-81%). The reaction is catalyzed by basic lead acetate, and is equally successful with both aliphatic and aromatic aldehydes. This mild version of the classical Erlenmeyer azlactone synthesis is apparently enabled by the enhanced aromaticity of the thioazlactone anion intermediate

New Approaches to the Cannizzaro and Tishchenko Reactions

It is demonstrated that the titled reactions are best carried out at high concentrations, as indicated by mechanistic considerations: the observed high reaction orders and the possibility that the Cannizzaro reaction is driven by the hydrophobic effect, which effects proximity between the two molecules of the aldehyde reactant. The present studies have led to improved conditions, simplified workup, and excellent yields of products. The Tishchenko reaction converted benzaldehyde to benzyl benzoate with catalytic NaOMe/tetrahydrafuran in good yield, which is apparently unprecedented for this product of high commercial value

Deracemization and Transacetalization of Aldehydes with Enantiomers of Betti's Base Derivatives

<div><p></p><p>Improved procedure for the deracemization of α-methyl dihydrocinnamic aldehydes (2-methyl-3-phenylpropanals) with L-(+)-tartaric acid salt of (<i>S</i>)-enantiomer of Betti's base, is presented. The method enabled the transacetalization of N,O-ketal (<i>R</i>)-enantiomer of Betti's base with various aldehydes.</p> </div

Design, synthesis, anticancer evaluation and molecular docking studies of 1,2,3-triazole incorporated 1,3,4-oxadiazole-Triazine derivatives

A new library of 1,2,3-triazole-incorporated 1,3,4-oxadiazole-triazine derivatives (9a-j) was designed, synthesized, and tested in vitro for anticancer activity against PC3 and DU-145 (prostate cancer), A549 (lung cancer), and MCF-7 (breast cancer) cancer cell lines using the MTT assay with etoposide as the control drug. The compounds exhibited remarkable anticancer activity, with IC50 values ranging from 0.16 ± 0.083 μM to 11.8 ± 7.46 μM, whereas the positive control ranged from 1.97 0.45 μM to 3.08 0.135 μM. Compound 9 d with a 4-pyridyl moiety shown exceptional anticancer activity against PC3, A549, MCF-7, and DU-145 cell lines, with IC50 values of 0.17 ± 0.063 μM, 0.19 ± 0.075 μM, 0.51 ± 0.083 μM, and 0.16 ± 0.083 μM, respectively

General hydroamination of allenamides: mechanistic Insights with an acetate adduct and 1,1,1,3,3,3-hexafluoro-2-propanol

The 1,1,1,3,3,3-hexafluoro-2-propanol-assisted allenamide activation enables metal-free regioselective intermolecular interception of amines, constituting a general C–N bond formation process for accessing value-added 1,3-diamines. Exclusive N-chemoselectivity (vs C for anilines) and regioselectivity were achieved for a broad range of substrates. Late-stage modification and further transformations of the 1,3-diamine products showcased the practicability and benefits of this strategy. Experimental mechanistic studies revealed that 1,1,1,3,3,3-hexafluoro-2-propanol mediates the proton transfer for activation of the allenamide. Density functional theory computations revealed the role of NaOAc in the formation of the reactive electrophilic intermediate, which ultimately governs the selective formation of the 1,3-diamine product