Phenanthroline and tert-butoxide have been established as powerful radical initiators in reactions such as the S(RN)1-type coupling reactions due to the cooperation of large heteroarenes and a special feature of tert-butoxide. The first phenanthroline-tert-butoxide-catalyzed transition-metal-free allylic isomerization is described. The resulting ketones are key intermediates for indenes. The control experiments rule out the base-promoted allylic anion pathway. The radical pathway is supported by experimental evidence that includes kinetic study, kinetic isotope effect, isotope-labeling experiments, trapping experiments, and EPR experiments.
Designed pincer ligand supported Co(<scp>ii</scp>)-based catalysts for dehydrogenative activation of alcohols: Studies on <i>N</i>-alkylation of amines, α-alkylation of ketones and synthesis of quinolines
作者:Anshu Singh、Ankur Maji、Mayank Joshi、Angshuman R. Choudhury、Kaushik Ghosh
DOI:10.1039/d0dt03748f
日期:——
Base-metal catalysts Co1, Co2 and Co3 were synthesized from designed pincerligands L1, L2 and L3 having NNN donor atoms respectively. Co1, Co2 and Co3 were characterized by IR, UV–Vis. and ESI-MS spectroscopic studies. Single crystal X-ray diffraction studies were investigated to authenticate the molecular structures of Co1 and Co3. Catalysts Co1, Co2 and Co3 were utilized to study the dehydrogenative
A novel and efficient method has been developed for the chemoselective conjugate reduction of α,β-unsaturatedketones with tosylhydrazine as a hydrogen source to the corresponding saturatedketones in moderate to good yields. The present protocol does not require the use of transitionmetal, and is efficient being applicable to a wide range of substrates (25 examples).
Iridium(I) complexes having an imidazol-2-ylidene ligand with benzylic wingtips efficiently catalyzed the β-alkylation of secondary alcohols with primary alcohols and acceptorless dehydrogenative cyclization of 2-aminobenzyl alcohol with ketonesthrough a borrowinghydrogen pathway. The β-alkylated alcohols, including cholesterol derivatives, and substituted quinolines were obtained in good yields
RhCl(CO)(PPh 3 ) 2 catalyzed α-alkylation of ketones with alcohols
作者:Rui Wang、Lina Huang、Zhengyin Du、Hua Feng
DOI:10.1016/j.jorganchem.2017.05.055
日期:2017.10
A simple and efficient method for α-alkylation of ketones with primary alcohols catalyzed by RhCl(CO)(PPh3)2 without additional additives under mild conditions is developed. It has a wide substrate scope, high atom-efficiency and chemoselectivity. It is an environmentally friendly method to build CC bond because water is the only byproduct.
bismuth-catalyzed conjugatereduction protocol that allows for the catalytic regioselective formation of substituted ketones from enones under mild conditions has been developed. We have shown for the first time that the combined poly(methylhydro)siloxane-malononitrile system can serve as an efficient reductant/reagent in 1,4-conjugate reduction of enones. The regioselectivity, efficiencies, and experimental