10.1016/j.inoche.2009.10.023
The research focuses on the synthesis and characterization of amino-salicylaldimine-palladium(II) complexes as efficient catalysts for Suzuki and Heck cross-coupling reactions, which are crucial for the synthesis of various organic compounds including natural products and pharmaceuticals. The study involves the preparation of these palladium complexes with different ligands, such as morpholine, piperidine, pyrrolidine, 4-methylpiperazin, and diisopropylamine, and their subsequent evaluation as catalysts under various reaction conditions. The complexes were characterized using techniques like IR spectrometry, 1H NMR, and elemental analysis, with the crystal structure of one complex confirmed by X-ray diffraction analysis. The effectiveness of these catalysts was tested in Suzuki reactions using 4-chlorobenzaldehyde with phenylboronic acid, optimizing the reaction conditions by varying solvents, bases, and temperatures. The Heck reaction was also explored with aryl bromides and different olefins. The study utilized GC-MS to determine the conversion yields of the reactions, providing a comprehensive analysis of the catalytic activities and the influence of electronic and steric factors on the reaction outcomes.
10.1246/bcsj.54.1844
The study investigates the synthesis of oxazolidines, thiazolidines, and 5,6,7,8-tetrahydro-1H,3H-pyrrolo[1,2-c]oxazole (or thiazole)-1,3-diones from β-hydroxy- or β-mercapto-α-amino acid esters. Aromatic aldehydes such as benzaldehyde, p-anisaldehyde, p-chlorobenzaldehyde, and p-nitrobenzaldehyde are used to react with amino acid ethyl esters like L-serine, 3-phenyl-DL-serine, L-threonine, or L-cysteine to form oxazolidines or thiazolidines. These compounds can then be converted into oxazoles and thiazoles through dehydrogenation using N-bromosuccinimide. Acetylation of oxazolidines and thiazolidines leads to N-acetylderivatives, which can undergo cyclization in the presence of anhydrous ZnCl? to form the tetrahydro-pyrrolo[1,2-c]oxazole (or thiazole)-1,3-diones. The study also explores the interaction of oxazolidines and thiazolidines with p-nitrobenzaldehyde and piperidine to form Mannich bases. The IR spectra of the synthesized compounds are analyzed, showing characteristic shifts and absorptions related to functional groups such as the ester group and the oxazole or thiazole ring.
10.1039/c0ob00644k
The study presents an efficient one-pot synthesis method for highly functional alkenes through a phosphine-catalyzed tandem three-component reaction involving aldehydes, alkyl vinyl ketones, and amides. The process utilizes either EtPPh2 or PPh3 as catalysts and achieves high yields (68–99%) with excellent stereoselectivity (E/Z ratios up to 98:2) within a total reaction time of 3 to 29.5 hours. The study also explores the scope of the reaction with various aryl- and heteroaryl-substituted aldehydes, amides, and alkyl vinyl ketones, demonstrating the versatility and practicality of the method. The reaction mechanism is proposed to involve a Morita–Baylis–Hillman reaction followed by a Michael addition, leading to the formation of the desired alkenes. The mild reaction conditions and the high atom economy of the process make it a valuable addition to organic synthesis.
F; 
C; 
N; 
Xn; 
Xi
