Rh-Catalyzed aldehydic C–H alkynylation and annulation
作者:Maddali L. N. Rao、Boddu S. Ramakrishna
DOI:10.1039/c9ob02670c
日期:——
aldehydic C-Hbond alkynylation and annulation for the in situ synthesis of chromones and aurones are described. It involves the sequential aldehydeC-Hbond alkynylation of salicylaldehyde with in situ generated 1-bromoalkyne from 1,1-dibromoalkene followed by annulation. This protocol shows good functional group tolerance including aryl, alkenyl, alkyl and heteroaryl-1,1-dibromoalkenes. The steric/electronic
The procedure consists of a sequence of some reactions including an arylation/decarboxylation cascade and proceeds well in aqueous media to afford biologically interesting flavones and 3-arylcoumarins. This method exhibited excellent selectivity and functional group tolerance under mild conditions. The reaction also showed perfect efficacy for the preparation of styryl coumarins.
使用K 2 S 2 O 8,实现了色农酮与芳基硼酸的高度区域选择性和无过渡金属的一锅芳基化反应。该程序由一系列反应组成,包括芳基化/脱羧级联,并在水性介质中进行得很好,从而提供了生物学上令人感兴趣的黄酮和3-芳基香豆素。该方法在温和条件下显示出极好的选择性和官能团耐受性。该反应还显示出制备苯乙烯基香豆素的完美功效。
One-pot Synthesis of Aurones through Oxidation-cyclization Tandem Reaction Catalyzed by Copper Nanoparticles Catalyst
作者:Min Yu、Guangxiang Liu、Chengyan Han、Li Zhu、Xiaoquan Yao
DOI:10.2174/1570178614666171110150853
日期:2017.12.11
Aurones were synthesized through an oxidation-cyclization tandemreaction of 2-(1- hydroxyprop-2-ynyl)phenols catalyzed by copper nanoparticles (Cu NPs) with bipyridine as the ligand. In the reaction, oxygen worked as a green and mild oxidant to give the best results. Cu NPs were dually activated by bipyridine ligand and water, and showed highly efficient catalytic activities to the oxygen oxidation
disclose a metal‐free and efficient method for the direct conversion of 2‐propynolphenols to biologically important flavones using aqueous HI as the promoter. This transformation was proved via 4‐iodo‐2H‐chromenes intermediate, which was simultaneously conversed to corresponding flavones by a Csp2–I bond cleavage and a C–O bond formation under air.