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
(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 multisubstitutednaphthalenes 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。
Palladium-Catalyzed Annulation of<i>vic</i>-Bis(pinacolatoboryl)alkenes and -phenanthrenes with 2,2′-Dibromobiaryls: Facile Synthesis of Functionalized Phenanthrenes and Dibenzo[<i>g</i>,<i>p</i>]chrysenes
Palladium-catalyzed double cross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls: annulative approach to functionalized polycyclic aromatic hydrocarbons
This study demonstrates that the doublecross-coupling reaction of 1,2-bis(pinacolatoboryl)alkenes and -arenes with 2,2′-dibromobiaryls proceeds smoothly with the aid of a catalytic amount of Pd(PPh3)4 in the presence of excess base to give a variety of polycyclic aromatic hydrocarbons, such as phenanthrenes, [5]helicene, dithienobenzenes, triphenylenes, dibenzo[g,p]chrysenes, and triphenyleno[1,2-b:4
这项研究表明,在催化量的Pd(PPh 3)4存在下,1,2-双(频哪醇硼基)烯烃和-芳烃与2,2'-二溴联芳基的双交叉偶联反应可以顺利进行。过量的碱可得到各种多环芳烃,例如菲,[5]螺旋烯,二硫代苯,三苯撑,二苯并[ g,p ],和三苯并[1,2- b:4,3- b ']二噻吩好到高产。值得注意的是,使用2,2'-二溴八氟联苯作为亲电试剂的环化反应提供了否则难以合成的八氟菲和半氟化二苯并[ g,p] chrysenes高产。