Nickel-catalyzed synthesis of 9-monoalkylated fluorenes from 9-fluorenone hydrazone and alcohols
作者:Jiang-Tao Fan、Xin-Heng Fan、Yong-Jie Chen、Cai-Yan Gao、Lian-Ming Yang
DOI:10.1080/00397911.2019.1647438
日期:——
Abstract A practical protocol was disclosed for the nickel-catalyzed C-alkylation of 9-fluorenone hydrazone with alcohols using t-BuOK as the base, and 9-monoalkylated fluorene derivatives were obtained in good yields under the benign conditions. GRAPHICAL ABSTRACT
By using aldehydes or ketones as the catalyst and screening CsOH out as the more effective base than KOH in many instances, an efficient 9-C-alkylation of fluorenes with alcohols was...
central goal in catalysis. This would be especially interesting when the reactivity and selectivity patterns can be tuned. Herein, we introduced the first Mn-catalyzed selective C-alkylation and olefination of fluorene, and indene with alcohols. Various substrates including benzylic, heteroaromatic, and aliphatic primary and secondary alcohols are employed as alkylating agents. Mechanistic investigations
<i>t</i>-BuOK-catalysed alkylation of fluorene with alcohols: a highly green route to 9-monoalkylfluorene derivatives
作者:Jiang-Tao Fan、Xin-Heng Fan、Cai-Yan Gao、Zhenpeng Wang、Lian-Ming Yang
DOI:10.1039/c9ra07557g
日期:——
A simple, mild and efficient protocol was developed for the alkylation of fluorene with alcohols in the presence of t-BuOK as catalyst, affording the desired 9-monoalkylfluorenes with near quantitative yields in most cases.
Ligand-Free Ru-Catalyzed Direct sp<sup>3</sup> C–H Alkylation of Fluorene Using Alcohols
作者:Moseen A. Shaikh、Sandip G. Agalave、Akash S. Ubale、Boopathy Gnanaprakasam
DOI:10.1021/acs.joc.9b02913
日期:2020.2.21
to excellent isolated yield (26 examples, 50-92% yield), whereas this reaction with secondary alcohols in the absence of any external oxidants furnished the tetrasubstituted alkene as the major product. Furthermore, a base-mediated C-H hydroxylation of the synthesized 9H-fluorene derivatives afforded 9H-hydroxy-functionalized quaternary fluorene derivatives in excellent yield.