K2CO3-Catalyzed Synthesis of Chromones and 4-Quinolones through the Cleavage of Aromatic C–O Bonds
摘要:
Phenol-derived electrophiles are favorable substrates because phenols are naturally abundant or can be readily prepared from other aromatic compounds. However, the cleavage of aromatic C-O bonds Is a great challenge because of their high energy. K2CO3-catalyzed intramolecular cyclization of 1-(2-alkoxyphenyl)-3-akylpropane-1,3-dlone and 3-(alkylimino)-1-(2-methoxyphenyl)-2-methylpropan-1-one derivatives via the selective cleavage of aromatic C-O bonds Is reported. The corresponding chromone and 4-quinolone derivatives were obtained in reasonable yields.
Stereoselective Hydrosilylation of 1,2‐Diketones Catalyzed by Chiral Frustrated Lewis Pairs
作者:Ting Liu、Wei Meng、Xiangqing Feng、Haifeng Du
DOI:10.1002/anie.202313957
日期:2024.1.25
A highly stereoselective hydrosilylation of unsymmetrical vicinal diketones with PhSiH3 was accomplished under the frustrated Lewis pair (FLP) catalysis, delivering 1,2-di-aryl-1,2-anti-diols in high yields with >99/1 dr values and up to 97 % ee. The chiral FLP catalyst exhibits the ability to control regio-, diastereo-, and enantioselectivities, while silane PhSiH3 facilitates an intramolecular hydrosilylation