Carbene transfer reactions play an important role in the field of organicsynthesis because of their ability to construct a variety of molecules. Herein, we reported on blue light-induced cyclopropenizations of N-tosylhydrazones in water, which avoids the use of expensive metal-based catalysts and toxic organic solvents. This metal-free and operationally simple methodology enable highly efficient cyclopropenizations
Metal‐free photochemical carbene‐transfer reactions of tosylhydrazones were developed under blue light irradiation at room temperature. This reaction constructs C−X (X=C, N, O, S) bonds and cyclopropanes from readily available and stable starting materials.
time-economical TfOH-catalyzed N–H insertion between anilines and α-alkyl and α-aryl-α-diazoacetates provides a straightforward approach to access unnatural α-amino esters, which readily undergo various transformations and can thus be used for the synthesis of pharmaceutically relevant molecules. The α-amino esters were obtained in moderate to excellent yields.
Fe<sup>II</sup>-catalysed insertion reaction of α-diazocarbonyls into X–H bonds (X = Si, S, N, and O) in dimethyl carbonate as a suitable solvent alternative
作者:Nour Tanbouza、Hoda Keipour、Thierry Ollevier
DOI:10.1039/c9ra07203a
日期:——
The insertion reaction of a broad range of diazo compounds into Si–H bonds was found to be efficiently catalysed by Fe(OTf)2 in an emerging green solvent i.e. dimethyl carbonate (DMC). The α-silylated products were obtained in good to excellent yields (up to 95%). Kinetic studies showed that the extrusion of N2 to form an iron carbene intermediate is rate-limiting. The iron-catalysed insertion reaction
into N−H bonds cocatalyzed by chiral phosphoricacid. Nitrogen dopants played a crucial role in both catalytic activity and enantioselectivity while almost no catalysis was observed with Rh nanoparticles immobilized on supports without nitrogen dopants. Various types of chiral α-amino acid derivatives were synthesized in high yields with high enantioselectivities and NCI-Rh could be reused in seven