Synthesis of Phenanthridine Derivatives by Microwave-Mediated Cyclization of o-Furyl(allylamino)arenes
摘要:
A novel and efficient synthesis of phenanthridines and aza analogues is reported. The key step is a microwave-mediated intramolecular Diels-Alder cyclization of o-furyl(allylamino)arenes. In the presence of a catalytic amount of acid, the DA-adduct reacts further to give the dihydrophenanthridines, which easily can be oxidized to fully aromatic compounds by air in the presence of UV light or by DDQ.
Organic Photoredox Catalysis for Pschorr Reaction: A Metal-Free and Mild Approach to 6H-Benzo[c]chromenes
作者:Gaofeng Feng、Jing-Yao He、Qi-Fan Bai、Chengan Jin
DOI:10.1055/s-0037-1610279
日期:2018.10
under mild conditions by using eosinY as a photoredox catalyst and acetonitrile as the solvent. The diazonium salts can be either preformed or generated in situ from the corresponding amines with t -BuONO. The process is amenable to gram-sale synthesis of 6 H -benzo[ c ]chromenes, which can be further transformed into both 6 H -benzo[ c ]chromen-6-ones through oxidation or to 6 H -benzo[ c ]chromen-6-amine
已开发出一种方便的有机光氧化还原 Pschorr 反应,为 6 H-苯并 [c] 色烯开辟了一条合成路线。该过程可以在温和的条件下通过使用曙红Y作为光氧化还原催化剂和乙腈作为溶剂进行。重氮盐可以由相应的胺与 t-BuONO 预先形成或原位生成。该工艺适用于6 H-苯并[ c ]色烯的克销售合成,其可以通过氧化进一步转化为6 H-苯并[ c ]色烯-6-酮或6 H-苯并[ c ]色烯-6-胺通过 sp 3 C-H 键胺化。该协议为合成 6 H-苯并 [c] 铬库提供了一条有吸引力的途径。
Visible light mediated synthesis of 6<i>H</i>-benzo[<i>c</i>]chromenes: transition-metal-free intramolecular direct C–H arylation
作者:Micaela D. Heredia、Marcelo Puiatti、Roberto A. Rossi、María E. Budén
DOI:10.1039/d1ob01673c
日期:——
A synthetic approach towards the 6H-benzo[c]chromene ring under visible light and transition-metal-free conditions has been developed. Benzochromenes are synthesized from the corresponding (2-halobenzyl) phenyl ethers or (2-halophenyl) benzyl ethers using KOtBu in dimethyl sulfoxide (DMSO) at room temperature (rt) and blue light-emitting diodes (LEDs) as the light source. This methodology replaces
已经开发了一种在可见光和无过渡金属条件下合成 6 H-苯并[ c ]色烯环的方法。苯并色烯是由相应的 (2-卤代苄基) 苯基醚或 (2-卤代苯基) 苄基醚在室温 (rt) 下使用二甲基亚砜 (DMSO) 中的 KO t Bu 和蓝色发光二极管 (LED) 作为光源合成的. 这种方法取代了配体或添加剂、高温和有毒溶剂的使用。光刺激反应对不同的官能团和 5 H-二苯并[ c , f]色烯也被有效地获得。发现了由二甲基阴离子和(2-卤代苄基)苯基醚形成的电子供体-受体复合物,它诱导 ET 作为光环化反应的第一步。此外,为了解释该反应的区域化学结果,使用 DFT 方法进行了理论分析。
Synthesis of Phenanthridine Derivatives by Microwave-Mediated Cyclization of <i>o</i>-Furyl(allylamino)arenes
作者:Matthew Lovell Read、Lise-Lotte Gundersen
DOI:10.1021/jo3027033
日期:2013.2.1
A novel and efficient synthesis of phenanthridines and aza analogues is reported. The key step is a microwave-mediated intramolecular Diels-Alder cyclization of o-furyl(allylamino)arenes. In the presence of a catalytic amount of acid, the DA-adduct reacts further to give the dihydrophenanthridines, which easily can be oxidized to fully aromatic compounds by air in the presence of UV light or by DDQ.