60323-09-3Relevant academic research and scientific papers
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.
Selective 1,2-Aryl-Aminoalkylation of Alkenes Enabled by Metallaphotoredox Catalysis
Chen, Zimin,Hu, Yuanyuan,Li, Weirong,Liao, Zixuan,Xi, Xiaoxiang,Yuan, Weiming,Zheng, Songlin
supporting information, p. 17910 - 17916 (2020/08/21)
A highly chemo- and regioselective intermolecular 1,2-aryl-aminoalkylation of alkenes by photoredox/nickel dual catalysis is described here. This three-component conjunctive cross-coupling is highlighted by its first application of primary alkyl radicals, which were not compatible in previous reports. The readily prepared α-silyl amines could be transferred to α-amino radicals by photo-induced single electron transfer step. The radical addition/cross-coupling cascade reaction proceeds under mild, base-free and redox-neutral conditions with good functional group tolerance, and importantly, provides an efficient and concise method for the synthesis of structurally valuable α-aryl substituted γ-amino acid derivatives motifs.
Catalyst free, visible-light promoted photoaddition reactions between C60 and N-trimethylsilylmethyl-substituted tertiary amines for synthesis of aminomethyl-1,2-dihydrofullerenes
Lim, Suk Hyun,Cho, Dae Won,Mariano, Patrick S.
, p. 383 - 391 (2017/12/28)
An efficient and benign method for the preparation of aminomethyl-substituted fullerenes has been developed. The process, involving catalyst free, visible-light irradiation of 10% EtOH-toluene solutions containing fullerene C60 and N-trimethyls
Dynamics of α-CH deprotonation and α-desilylation reactions of tertiary amine cation radicals
Zhang, Xiaoming,Yeh, Syun-Ru,Hong, Seok,Freccero, Mauro,Albini, Angelo,Falvey, Daniel E.,Mariano, Patrick S.
, p. 4211 - 4220 (2007/10/02)
Time-resolved laser spectroscopy has been used to generate and characterize a series of tertiary amine cation radicals and to determine the rates of their α-CH deprotonation and α-desilylation reactions with bases and silophiles. Laser excitation (308 nm) of a 60:40 MeOH:MeCN solution of PhNMe2 (DMA) and 1,4-dicyanobenzene (DCB) promotes SET-induced formation of the DMA cation radical (460 nm) and DCB anion radical (340 nm), which undergo decay by back electron transfer at nearly equal rates and with respective second-order rate constants of 1.1 × 1010 and 1.3 × 1010 M-1 s-1 (25°C). The decay rate is lowered (ca. 4-fold) by the inclusion of salts (ca. 0.1 M) such as nBu4NClO4, LiClO4, HBu4NCl, nBu4NBF4, and nBu4NO3SCF3 in MeOH-MeCN and by changing the solvent from MeCN to MeOH and to EtOH. The cation radical of PhNMeCH2(TMS) (480 nm) and the simultaneously generated DCB anion radical undergo second order decay in MeCN with respective rate constants of 1.2 × 1010 and 9.9 × 109 M-1 s-1 (25°C). The silylamine cation radical decay rate was found to be governed by the concentration of silophiles (MeOH, H2O and nBu4NF) in MeCN solutions. The observations are consistent with a silophile-induced desilylation process with second-order rate constants of 8.9 × 105 (MeOH), 1.27 × 106 (H2O), and 3.1 × 109 M-1 s-1 (nBu4NF). The rate of DMA cation radical decay is a function of base concentration. Both nBu4NOAc and nBu4NO2CCF3 react with the DMA cation radical (in 60:40 MeOH:MeCN containing 0.1 M nBu4NClO4) with second-order rate constants for α-CH deprotonation of 3.1 × 105 and 8 × 104 M-1 s-1 (25°C), respectively. Measurements with PhN(CD3)2 and nBu4NOAc gave a kH/kD for α-CH deprotonation of 3.6 (60:40 MeOH:MeCN, 25°C). Para-substituents have a pronounced effect on the rate of α-CH deprotonation by nBu4NOAc; second-order rate constants of 2.3 × 104, 1.1 × 105, and 2.5 × 106 M-1 s-1 were determined for the P-OMeC6H4NMe2, p-MeC6H4NMe2 and p-CF3C6H4NMe2 cation radicals. Studies with Ph2NMe demonstrated that its cation radical (645 nm) can be generated by SET to DCB and that its decay through α-CH deprotonation by nBu4NOAc has a second-order rate constant of 9.5 × 105 M-1 s-1 and a kH/kD value of 2.8 (25:75 MeOH:MeCN, 25°C). Finally, the effects of α-substituents on the rates of nBu4-NOAc-induced α-CH deprotonation of tertiary amine cation radicals were evaluated by use of the amines Ph2NCHR1R2. The second-order rate constants (25°C, 25:75 MeOH:MeCN) are 2.3 × 105 (R1 = Me, R2 = H), 1.7 × 105 (R1 = R2 = Me), 3.2 × 106 (R1 = Ph, R2 = H), 2.6 × 106 (R1 = CH=CH2, R2 = H), and 7.0 × 107 M-1 s-1 (R1 = C≡CH, R2 = H).
Pentacoordinate silicon intermediates in relay substitution reactions of organosilanes: successive nucleophilic attack at silicon and its adjacent carbon
Eisch, John J.,Chiu, Chingchen S.
, p. C1 - C5 (2007/10/02)
Chloromethylsilyl chlorides of the type, ClCH2R2SiCl, have been shown to undergo kinetically controlled nucleophilic attack at silicon, with either phenols or amines (PhEH, with E=O or NMe), to yield products of the type, PhESiR2CH2Cl.Subsequent treatment of the latter products with KF in acetonitrile causes the nucleophile to be shifted from silicon to carbon with the formation of FSiR2CH2EPh.Alternatively, treatment of ClCH2R2SiCl simultaneously with PhEH and KF yields the same thermodynamically controlled product directly, FSiR2CH2EPh.This possibility of directing nucleophilic attack toward silicon or its adjacent carbon has great importance in the synthesis of substituted organosilanes.The mechanism of these so-called relay nucleophilic substitutions is proposed as involving pentacoordinate silicon intermediates.The concept of initial nucleophilic attack at silicon and the subsequent relaying of the nucleophile from the pentacoordinate silicon to the adjacent carbon is also shown to be applicable to the unusual reactions of α,β-epoxyalkylsilanes.
