Straightforward synthesis of phenanthrenes from styrenes and arenes
作者:Hu Li、Ke-Han He、Jia Liu、Bi-Qin Wang、Ke-Qing Zhao、Ping Hu、Zhang-Jie Shi
DOI:10.1039/c2cc33100d
日期:——
Semi-one-pot synthesis of phenanthrenesfrom styrenes and arenes was developed through cross-dehydrogenative coupling. A sequence of Heck-type coupling and photo-cyclization were involved and a variety of functionalities were tolerated. This method provides an effective and practical protocol towards the synthesis of substituted phenanthrenes.
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。
Triflic acid promoted synthesis of polycyclic aromatic compounds
作者:Ang Li、Daniel J. DeSchepper、Douglas A. Klumpp
DOI:10.1016/j.tetlet.2009.02.042
日期:2009.4
The triflic acid (CF3SO3H) promoted cyclizations of 2-styrylbiaryls are found to be useful for the synthesis of polycyclic aromatic compounds, including functionalized derivatives of polycyclic aromatic compounds and heterocyclicsystems. The reaction involves cationic cyclization followed by an elimination of benzene from the intermediate product.
发现三氟甲磺酸(CF 3 SO 3 H)促进的2-苯乙烯基联芳基的环化可用于合成多环芳族化合物,包括多环芳族化合物的官能化衍生物和杂环体系。该反应涉及阳离子环化,然后从中间产物中消除苯。
The first example of formation of the benzyne intermediate from the reactions of selenonium salts with phenyllithium
The reaction of diphenyl(phenylethynyl)selenonium salt 1a with 1.0 equiv. of phenyllithium afforded 1,4-diphenylbutadiyne 5 and 1-(o-biphenylyl)-2-phenylethyne 7 in 25% and 15% yields, respectively. The latter product 7 was formed via the benzyneintermediate.
Construction of Alkylidene Fluorene Scaffolds Using Pd-Catalyzed Direct Arene/Alkene Coupling Strategy
作者:Hidenori Matsuyama、Xuan Zhang、Masahiro Terada、Tienan Jin
DOI:10.1021/acs.orglett.2c04307
日期:2023.2.10
alkylidene fluorenes and their heteroarene derivatives has been developed successfully by means of a Pd(II)-catalyzed direct C–H/C–H coupling of o-alkenyl biaryls. Use of the Pd(OAc)2 catalyst under aerobic oxidation conditions gives rise to the corresponding alkylidene fluorenes having various functional groups and diversely fused polycyclic systems. The resulting products can serve as versatile synthetic