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.
Herein, we described the selective synthesis of both alkylated and alkenylated fluorenes using a single SNS ligand derived nickel complex. The protocol was employed for a wide range of substrates, including substituted fluorenes and various alcohols including aliphaticalcohols with a distal double bond. To expand the synthetic utility, an antimalarial drug analogue, benflumetol, was synthesized, and