Novel Syntheses of Fluorenones via Nitrile-Directed Palladium-Catalyzed C–H and Dual C–H Bond Activation
摘要:
Novel procedures for the [Pd]/[Ag]/TFA system catalyzed cascade reactions of nitrile directed remote C-H and dual C-H bond activation with insertion of nitrile were developed, which afforded variously polysubstituted fluorenones in moderate to good yields with tolerance of a wide variety of substrates.
Synthesis of highly substituted fluorenones via metal-free TBHP-promoted oxidative cyclization of 2-(aminomethyl)biphenyls. Application to the total synthesis of nobilone
作者:Ilya A P Jourjine、Lukas Zeisel、Jürgen Krauß、Franz Bracher
DOI:10.3762/bjoc.17.181
日期:——
Highlysubstituted fluorenones are readily prepared in mostly fair to good yields via metal- and additive-free TBHP-promoted cross-dehydrogenative coupling (CDC) of readily accessible N-methyl-2-(aminomethyl)biphenyls and 2-(aminomethyl)biphenyls. This methodology is compatible with numerous functional groups (methoxy, cyano, nitro, chloro, and SEM and TBS-protective groups for phenols) and was further
通过不含金属和添加剂的 TBHP 促进的易于获得的N-甲基-2-(氨甲基)联苯和 2-(氨甲基)联苯的交叉脱氢偶联 (CDC),可以轻松制备高度取代的芴酮,收率基本上相当到良好。该方法与多种官能团(甲氧基、氰基、硝基、氯以及苯酚的 SEM 和 TBS 保护基团)兼容,并进一步用于天然产物诺比隆的首次全合成。
Benzene-Free Synthesis of Multisubstituted Catechol via Oxidative Dearomatic Reorganization
作者:Tongxiang Cao、Qiu Shi、Shifa Zhu
DOI:10.1021/acs.orglett.1c00071
日期:2021.2.19
multisubstituted catechol via an oxidative dearomatic reorganization is reported. This reaction tolerated a wide spectrum of functionalities, which could be applied in the synthesis of an electron-deficient arene-conjugated catechol that is difficult to access via biomimetic oxidative coupling. In addition, a diversification-oriented transformation that leveraged the versatile catechol afforded a series
Direct Excitation of Aldehyde to Activate the C(
<i>sp</i>
<sup>
<i>2</i>
</sup>
)−H Bond by Cobaloxime Catalysis toward Fluorenones Synthesis with Hydrogen Evolution
highly reactive photoexcited triplet state of aromatic aldehyde intermediates is intercepted by the catalyst in the ground state, thus leading to the synthesis of a series of fluorenones, xanthones and thioxanthones in good to excellent yields without any external oxidants and with hydrogen as the byproduct.
已经成功开发了通过钴肟催化直接激发醛以激活其 C ( sp 2 )-H 键。在照射下,芳香醛中间体的高反应性光激发三重态被基态催化剂拦截,从而导致在没有任何外部氧化剂和氢作为副产品。