The reaction of aryl iodides and bromides with acrolein diethyl acetal in the presence of Pd(OAc)(2), (n)()Bu(4)NOAc, K(2)CO(3), KCl, and DMF, at 90 degrees C until the disappearance of the acetal followed by the addition of 2 N HCl to the crude reaction mixture, affords cinnamaldehydes in good to high yields. A variety of functional groups are tolerated in the aryl halides, including ether, aldehyde
芳基碘化物和溴化物与丙烯醛二乙缩醛在Pd(OAc)(2),(n)()Bu(4)NOAc,K(2)CO(3),KCl和DMF存在下的反应,于90直至乙缩醛消失,然后向粗制反应混合物中加入2 N HCl,可以得到高至高收率的肉桂醛。芳基卤化物中可耐受多种官能团,包括醚,醛,酮,酯,二烷基氨基,腈基和硝基。靠近氧化加成位点的取代基的存在不妨碍反应。
Synthesis of Benzothiophene‐Fused Oxa[6.6.5]tricyclic Skeletons through a Cinchonidine‐ or NaOH‐Promoted Quadruple Domino Sequence
Two base‐promotedquadrupledomino reactions between thioaurones and allylic phosphonium salts have been developed to synthesize benzothiophene‐fusedoxa[6.6.5]tricyclicskeletons in moderate to good yields with excellent stereoselectivity and broad functional‐group tolerance. This is a simple and useful protocol for the rapid construction of the umbrella‐like oxa[6.6.5]tricyclicskeleton.