80500-11-4Relevant academic research and scientific papers
Development of a Simple Adjustable Zinc Acid/Base Hybrid Catalyst for C?C and C?O Bond-Forming and C?C Bond-Cleavage Reactions
Yamashita, Yasuhiro,Minami, Kodai,Saito, Yuki,Kobayashi, Shū
, p. 2372 - 2376 (2016)
A newly designed zinc Lewis acid/base hybrid catalyst was developed. By adjusting the Lewis acidity of the zinc center, aldol-type additions of 2-picolylamine Schiff base to aldehydes proceeded smoothly to afford syn-aldol adduct equivalents, trans-N,O-acetal adducts, in high yields with high selectivities. NMR experiments, including microchanneled cell for synthesis monitoring (MICCS) NMR analysis, revealed that anti-aldol adducts were formed at the initial stage of the reactions under kinetic control, but the final products were the trans-(syn)-N,O-acetal adducts that were produced through a retro-aldol process under thermodynamic control. In the whole reaction process, the zinc catalyst played three important roles: i) promotion of the aldol process (C?C bond formation), ii) cyclization process to the N,O-acetal product (C?O bond formation), and iii) retro-aldol process from the anti-aldol adduct to the syn-aldol adduct (C?C bond cleavage and C?C bond formation).
