Pd-catalysed carbonylative annulation of salicylaldehydes with benzyl chlorides using<i>N</i>-formylsaccharin as a CO surrogate
作者:Vinod K. Yadav、Vishnu P. Srivastava、Lal Dhar S. Yadav
DOI:10.1039/c8nj03173h
日期:——
A highly efficient synthesis of 3-arylcoumarins by Pd-catalysed carbonylative cyclisation of salicylaldehydes with benzyl chlorides usingN-formylsaccharin as a CO source is developed.
以 N-甲酰基糖精为 CO 源,通过 Pd 催化水杨醛与苄基氯的羰基化环化,开发了一种高效合成 3-芳基香豆素的方法。
Zn(II)-Catalyzed One-Pot Synthesis of Coumarins from Ynamides and Salicylaldehydes
作者:Huen Ji Yoo、So Won Youn
DOI:10.1021/acs.orglett.9b01181
日期:2019.5.3
A highly efficient and straightforward synthesis of diversely substituted coumarins from ynamides and salicylaldehydes in the presence of Zn(II) catalyst has been developed. The sulfonamide moiety of ynamides was successfully recycled in this process, serving as an effective traceless directing group for high regioselectivity in the bond-forming event. The advantages of this protocol are good functional
dehydrogenative direct radical arylation of coumarins with arylboronicacids to afford 3-arylcoumarin derivatives is described. A similar reaction system is also applicable to the 3-arylation of quinolinone derivatives. These KMnO4/AcOH-mediated coupling reactions occur regioselectively at the C3 position of coumarins and quinolinones. Some notable features of this method are high efficiency, moderate
Ph3P/I2–Et3N-mediated one-pot two-step esterification–cyclization toward 3-aryl coumarins and 3-aryl-4-methylcoumarins is reported. The reaction of a variety of aryl acetic acids containing steric or reactive group with 2-hydroxybenzaldehydes or 2′-hydroxyacetophenone proceeded smoothly at room temperature to afford the corresponding products in good to excellent yields using inexpensive and readily
Three-component coupling using arynes and DMF: straightforward access to coumarins via ortho-quinone methides
作者:Hiroto Yoshida、Yu Ito、Joji Ohshita
DOI:10.1039/c1cc11955a
日期:——
ortho-Quinone methides, arising from a formal [2+2] cycloaddition between arynes and DMF, were found to facilely undergo a [4+2] cycloaddition with ester enolates or ketenimine anions to produce diverse coumarins in a straightforward manner.