33709-40-9Relevant academic research and scientific papers
Iron-Catalysed Remote C(sp3)?H Azidation of O-Acyl Oximes and N-Acyloxy Imidates Enabled by 1,5-Hydrogen Atom Transfer of Iminyl and Imidate Radicals: Synthesis of γ-Azido Ketones and β-Azido Alcohols
Torres-Ochoa, Rubén O.,Leclair, Alexandre,Wang, Qian,Zhu, Jieping
, p. 9477 - 9484 (2019/05/21)
In the presence of a catalytic amount of iron(III) acetylacetonate [Fe(acac)3], the reaction of structurally diverse ketoxime esters with trimethylsilyl azide (TMSN3) afforded γ-azido ketones in good to excellent yields. This unprecedented distal γ-C(sp3)?H bond azidation reaction went through a sequence of reductive generation of an iminyl radical, 1,5-hydrogen atom transfer (1,5-HAT) and iron-mediated redox azido transfer to the translocated carbon radical. TMSN3 served not only as a nitrogen source to functionalise the unactivated C(sp3)?H bond, but also as a reductant to generate the catalytically active FeII species in situ. Based on the same principle, a novel β-C(sp3)?H functionalisation of alcohols via N-acyloxy imidates was subsequently realised, leading, after hydrolysis of the resulting ester, to β-azido alcohols, which are important building blocks in organic and medicinal chemistry.
Substituent Effects. XVI. Acetolysis of 2-Phenylethyl Tosylates
Fujio, Mizue,Funatsu, Kimito,Goto, Mutsuo,Seki, Yoji,Mishima, Masaaki,Tsuno, Yuho
, p. 1091 - 1096 (2007/10/02)
The acetolysis rates of 2-arylethyl tosylates were determined for a series of aryl substituents.The non-linear substituent effect was reasonably accounted for on the basis of two linear LArSR relationships; one for the aryl-assisted (FkΔ) and one for the unassisted (Ks) process, respectively.A precise dissection of the apparent substituent effect into individual effects for both processes was achieved in this manner.The substituent effect on the ks process can be described as a linear function of ?0 with a small ρs of -0.19, and that on the FkΔ process in terms of the LArSR Eq., with a ρΔ=-3.87 and an rΔ=0.631.The use of ?+ for the FkΔ process failed to give any reasonable dissection.The r value for this FkΔ process is essentially identical to that for the neophyl solvolysis.The unique r value oh 0.6 is concluded to be characteristic of β-aryl-assisted ionization processes in general.
