Shimizu Masaki, Kurahashi Takuya, Shimono Katsuhiro, Tanaka Kei, Nagao Ikuhiro, Kiyomoto Shin-ichi, Hiyama Tamejiro
Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Katsura Campus, Nishikyo-ku, Kyoto 615-8510, Japan.
Chem Asian J. 2007 Nov 5;2(11):1400-8. doi: 10.1002/asia.200700120.
Treatment of 1,1-bis(pinacolatoboryl)ethene with an excess of 1-bromo-1-lithioethene gave 2,3-bis(pinacolatoboryl)-1,3-butadiene in high yield. Palladium-catalyzed cross-coupling of the resulting diborylbutadiene with aryl iodides took place smoothly in the presence of a catalytic amount of Pd(OAc)2/PPh3 and aqueous KOH to give 2,3-diaryl-1,3-butadienes in good yields. The coupling reaction with commercially available 4-acetoxyphenylmethyl chloride under the same conditions followed by hydrolysis of the acetyl groups gave anolignan B in a one-pot manner. A variety of [3]- to [6]dendralenes were synthesized by palladium-catalyzed coupling of the diene or 1,1-bis(pinacolato)borylethene with alkenyl or dienyl halides, respectively, in good yields.
用过量的1-溴-1-锂代乙烯处理1,1-双（频哪醇硼酸酯）乙烯，以高收率得到2,3-双（频哪醇硼酸酯）-1,3-丁二烯。在催化量的Pd(OAc)₂/PPh₃和氢氧化钾水溶液存在下，所得二硼基丁二烯与芳基碘的钯催化交叉偶联反应顺利进行，以良好的收率得到2,3-二芳基-1,3-丁二烯。在相同条件下，与市售的4-乙酰氧基苯基甲基氯进行偶联反应，随后乙酰基水解，一锅法得到阿诺木脂素B。通过钯催化二烯或1,1-双（频哪醇硼酸酯）乙烯分别与烯基或二烯基卤化物的偶联反应，以良好的收率合成了多种[3]-至[6]轮烯。
