N-Unsubstituted hydrazones of somearomaticketones and aldehydes were found to react with lead tetraacetate giving the corresponding diazo compounds as primary reaction products, and the derived 1-monoacetoxy- and 1,1-diacetoxy-1-arylalkanes, as well as azines, as final products. The yields obtained depend on the stability of the diazo compound initially formed and on the experimental conditions employed
Formation of Benzylidenes-Diacetates Catalyzed by Activated Zeolite “LZY-562” and Clay (K10/ZnCl2): An Unexpected Functional Selectivity
作者:H. Dokari、M. Hammadi、N. Benferrah、Y. Rachedi
DOI:10.14233/ajchem.2015.15881
日期:——
Activated zeolites LZY-562 and clay montmorillonite K10 at room temperature without solvent catalyzes the synthesis of benzylidenes-diacetates from carbonyl compounds. A chemoselectivity was observed between aldehydes and ketones, between the different aldehydes and ketones as well.
Benzaldehydes are reduced by metallic zinc in the presence of Ac2O and imidazole, giving the corresponding benzyl acetates in good yields. Reductive esterification of aromatic aldehydes is also carried out via gem-diacetoxy compounds. Carbonylcompounds are readily converted to the gem-diacyloxy compounds in excellent yields on treatment with 2 molar amounts of acid anhydride and 10 mol% of Yb(OTf)3
Polystyrene-Supported, Al(OTf)<sub>3</sub>-Catalyzed Chemoselective Synthesis of Acylals from Aldehydes
作者:Kaveh Parvanak Boroujeni
DOI:10.1080/00397910903537323
日期:2010.12.22
Cross-linked polystyrene-supported aluminium triflate [Ps-Al(OTf)3] has been shown to be a mild, efficient, and chemoselective heterogeneous Lewis acid catalyst for acetylation of aldehydes with acetic anhydride. The catalyst can be recovered simply and reused efficiently at least five times without any noticeable loss of catalytic activity.