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...
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
Noninnocent Azo-Aromatic Cobalt(II)-Catalyzed sp<sup>3</sup> C–H Alkylation of Fluorenes with Alcohols
作者:Kamal、Subhas Samanta
DOI:10.1021/acs.joc.3c02657
日期:2024.2.2
well as both C–C and the C–N alkylation reaction of fluorenes was observed with this catalytic protocol. Such selective single-step dialkylation of fluorenes is indeed beneficial. Several control experiments, deuterium labeling, and 1H NMR kinetic studies have revealed a ligand radical-based borrowing hydrogen mechanism involving the azo-aromatic complexes of cobalt as catalysts for the alkylation of fluorenes