533935-67-0Relevant articles and documents
Copper catalyzed: N-formylation of α-silyl-substituted tertiary N-alkylamines by air
Bruce, Lachlan David,Chan, Philip Wai Hong,Jin, Jianwen,Xia, Bo,Zhao, Yichao
supporting information, p. 5296 - 5302 (2020/09/17)
A site-selective method to prepare N-formyl amines efficiently that relies on the copper(i)-catalyzed oxidation of α-silyl-substituted tertiary N-alkylamines by air at room temperature is described. The oxidative protocol was shown to exhibit excellent functional group tolerance as it was applicable to a wide variety of amine substrates and a number of bioactive molecules and natural products. Moreover, it delinates a ligand-and additive-free amine oxidation process mediated by a low-cost metal salt with oxygen from air taking on the role of both the terminal oxidant and as part of the formylation reagent, which is unprecedented in copper catalysis. It also offers the first synthetic method that can selectively generate α-amino radical species as reactive intermediates from α-silylamines under non-photochemical reaction conditions.
Methyl-Selective α-Oxygenation of Tertiary Amines to Formamides by Employing Copper/Moderately Hindered Nitroxyl Radical (DMN-AZADO or 1-Me-AZADO)
Nakai, Satoru,Yatabe, Takafumi,Suzuki, Kosuke,Sasano, Yusuke,Iwabuchi, Yoshiharu,Hasegawa, Jun-ya,Mizuno, Noritaka,Yamaguchi, Kazuya
supporting information, p. 16651 - 16659 (2019/11/11)
Methyl-selective α-oxygenation of tertiary amines is a highly attractive approach for synthesizing formamides while preserving the amine substrate skeletons. Therefore, the development of efficient catalysts that can advance regioselective α-oxygenation at the N-methyl positions using molecular oxygen (O2) as the terminal oxidant is an important subject. In this study, we successfully developed a highly regioselective and efficient aerobic methyl-selective α-oxygenation of tertiary amines by employing a Cu/nitroxyl radical catalyst system. The use of moderately hindered nitroxyl radicals, such as 1,5-dimethyl-9-azanoradamantane N-oxyl (DMN-AZADO) and 1-methyl-2-azaadamanane N-oxyl (1-Me-AZADO), was very important to promote the oxygenation effectively mainly because these N-oxyls have longer life-times than less hindered N-oxyls. Various types of tertiary N-methylamines were selectively converted to the corresponding formamides. A plausible reaction mechanism is also discussed on the basis of experimental evidence, together with DFT calculations. The high regioselectivity of this catalyst system stems from steric restriction of the amine-N-oxyl interactions.
