Palladium‐Catalyzed Annulation of 1,2‐Diborylalkenes and ‐Arenes with 1‐Bromo‐2‐[(
<i>Z</i>
)‐2‐bromoethenyl]arenes: A Modular Approach to Multisubstituted Naphthalenes and Fused Phenanthrenes
作者:Masaki Shimizu、Yosuke Tomioka、Ikuhiro Nagao、Tsugumi Kadowaki、Tamejiro Hiyama
DOI:10.1002/asia.201200132
日期:2012.7
(Z)‐1,2‐Diaryl‐1,2‐bis(pinacolatoboryl)ethenes underwent double‐cross‐coupling reactions with 1‐bromo‐2‐[(Z)‐2‐bromoethenyl]arenes in the presence of [Pd(PPh3)4] as a catalyst and 3 M aqueous Cs2CO3 as a base in THF at 80 °C. The double‐coupling reaction gave multisubstituted naphthalenes in good to high yields. Annulation of 1,2‐bis(pinacolatoboryl)arenes with bromo(bromoethenyl)arenes in the presence
(Ž)-1,2-二芳基-1,2-双(频哪醇基硼)ethenes后行双交叉偶联反应用1-溴-2 - [(ż)-2-溴乙烯基]在[钯的存在下芳烃(在80°C下于THF中作为催化剂的PPh 3)4 ]和作为碱的3 M Cs 2 CO 3水溶液。双重偶联反应以良好或高收率得到了多取代萘。在由[Pd 2(dba)3](dba =二亚苄基丙酮)和2-二环己基膦基2',6'-二甲氧基联苯(SPhos)在相同条件下可生产高产量的稠合菲。第一次环偶联发生在溴乙烯基基团区域上。此程序适用于通过使用相应的二溴双[[ Z)-2-溴乙烯基]苯作为二硼烷基偶联伙伴的双环途径轻松合成多取代的蒽,苯并噻吩和二苯并蒽。