The 1,3-dipolar cycloaddition between glycine-derived azlactones with maleimides is efficiently catalyzed by the dimeric chiral complex [(S a)-Binap·AuTFA]2. The alanine-derived oxazolone only reacts with tert-butyl acrylate giving anomalous regiochemistry, which is explained and supported by Natural Resonance Theory and Nucleus Independent Chemical Shifts calculations. The origin of the high e...

The acid property of alkali and alkali earth cation exchanged clinoptiolites were observed by micro-calorimetry of NH(3) adsorption at 200 degrees C. The reaction rates on decomposition of tert-butyl acetate (TBA) over clinoptilolites was proportional to the acid strength. 1,4-Dihydropyridines were oxidized to corresponding Pyridines in high yields at room temperature by H(2)O(2) aqueous soluti...

An efficient enantioselective synthetic method for the synthesis of (2R)-5-phenyl-2-alkylproline tert-butyl esters was reported. The phase-transfer catalytic alkylation of tert-butyl-5-phenyl-3,4-dihydro-2H-pyrrole-2-carboxylate in the presence of chiral quaternary ammonium catalysts gave the corresponding alkylated products (up to 97% ee). The following diastereoselective reductions afforded c...

The title compound, C(21)H(26)N(2)O, was obtained as an unexpected by-product when attempting to prepare (S)-2-benzyl-N-tert-butyl-1,2,3,4-tetra-hydro-isoquinoline-3-carboxamide from (S)-2-benzyl-amino-N-tert-butyl-3-phenyl-propanamide and dimethoxy-methane. The mol-ecules are linked by weak C-H⋯O hydrogen bonds, generating linear chains parallel to the b axis. C-H⋯π inter-actions provide furth...

Multicobalt(II) two-dimensional layer coordination polymer {[Co(bitbu-OMe)2(NCS)2]·2MeOH}n (1) was synthesized using a bis-imidazole ligand having steric hindrance, tert-butyl, and one methoxy group expressed by bitbu-OMe (bitbu-OMe = 1,1′-[(5-tert-butyl-2-methoxybenzene-1,3-diyl)dimethanediyl]bis(1H-imidazole). Since there are two methanol molecules trapped inside each void within 1, the inves...

Key words protecting groups - selective deprotection cerium(III) chloride sodium iodide

Objective : to assess the subchronic toxicity of bis(3,5-di-tert-butyl-4-hydroxyphenyl)dimethyltin (Me-3) and (3,5-di-tert-butyl-4-hydroxyphenyl)triphenyltin (Me-5) with identification external signs changes in indicators functional state liver kidneys Wistar rats (females) 14-fold daily intragastric injection simulate a metronomic chemotherapy regimen. Materials method study was conducted on 2...

In the crystal structure of the title compound, C(25)H(30)N(2)O(4), the steric size of the tert-butyl group causes the 3,5-dimethyl-phenyl ring to adopt a transoid geometry with respect to the N-C(O) bond. The six-membered heterocyclic ring is disordered over two sites, with occupancies of 0.553 (4) and 0.447 (4). Intra-molecular C-H⋯O inter-actions are present. In the crystal, mol-ecules are l...