17877-17-7Relevant articles and documents
Metal-Free Aminomethylation of Aromatic Sulfones Promoted by Eosin Y
Thierry, Thibault,Pfund, Emmanuel,Lequeux, Thierry
supporting information, p. 14826 - 14830 (2021/10/01)
A metal-free α-aminomethylation of heteroaryls promoted by eosin Y under green light irradiation is reported. A large variety of α-trimethylsilylamines as precursor of α-aminomethyl radical species were engaged to functionalize sulfonyl-heteroaryls following a Homolytic Aromatic Substitution (HAS) pathway. This method has provided a range of α-aminoheteroaryl compounds including a functionalized natural product. The mechanism of this late-stage functionalization of aryls was investigated and suggests the formation of a sulfonyl radical intermediate over a reductive quenching cycle.
1,2-Amino Alcohols via Cr/Photoredox Dual-Catalyzed Addition of α-Amino Carbanion Equivalents to Carbonyls
Schwarz, J. Luca,Kleinmans, Roman,Paulisch, Tiffany O.,Glorius, Frank
supporting information, p. 2168 - 2174 (2020/03/03)
Herein, we report the synthesis of protected 1,2-amino alcohols starting from carbonyl compounds and α-silyl amines. The reaction is enabled by a Cr/photoredox dual catalytic system that allows the in situ generation of α-amino carbanion equivalents which act as nucleophiles. The unique nature of this reaction was demonstrated through the aminoalkylation of ketones and an acyl silane, classes of electrophiles that were previously unreactive toward addition of alkyl-Cr reagents. Overall, this reaction broadens the scope of Cr-mediated carbonyl alkylations and discloses an underexplored retrosynthetic strategy for the synthesis of 1,2-amino alcohols.
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.
Photolysis of Tertiary Amines in the Presence of CO2: The Paths to Formic Acid, α-Amino Acids, and 1,2-Diamines
Berton, Mateo,Mello, Rossella,Acerete, Rafael,González Núnez, María Elena
, p. 96 - 103 (2018/02/19)
The photolysis of triethylamine (1a) in the presence of carbon dioxide leads to the hydrogenation of CO2, the α-C-C coupling of 1a, and the CO2 insertion into the α-C-H σ-bond of amine 1a. This reaction is proposed to proceed through the radical ion pair [R3N?+·CO2?-] generated by the photoionization of amine 1a and the electron capture by CO2. The presence of lithium tetrafluoroborate in the reaction medium promotes the efficient and stereoselective α-C-C coupling of 1a by enhancing the production of α-dialkylamino radicals and the isomerization of N,N,N′,N′-tetraethylbutane-2,3-diamine (4a).
Selective Si?C(sp3) Bond Cleavage in (Aminomethyl)silanes by Carbanionic Nucleophiles and Its Stereochemical Course
Koller, Stephan G.,Bauer, Jonathan O.,Strohmann, Carsten
supporting information, p. 7991 - 7994 (2017/06/27)
Selective cleavage of a silicon–carbon bond in tetraorganosilanes is still a great challenge. A new type of Si?C(sp3) bond cleavage in bench-stable (aminomethyl)silanes with common organolithium reagents as nucleophiles has now been identified. Suitable leaving groups are benzyl, allyl, and phenylthiomethyl groups. A β-donor function and polar solvents are essential for the reaction. Simple switching between α-deprotonation and substitution is possible through slight modifications of the reaction conditions. The stereochemical course of the reaction was elucidated by using a silicon-chiral benzylsilane. The new transformation proceeds stereospecifically with inversion of configuration and can be used for the targeted synthesis of enantiomerically pure tetraorganosilanes, which are otherwise difficult to access. Quantum chemical calculations provided insight into the mechanism of the new substitution.
NITROGEN-CONTAINING ORGANOSILICON COMPOUNDS. 150. SYNTHESIS AND CHROMATOGRAPHIC AND 1H, 13C, 15N, AND 29Si NMR SPECTROSCOPIC INVESTIGATION OF SUBSTITUTED (PIPERIDINOALKYL)SILANES
Lukevits, E.,Sleiksha, I.,Liepin'sh, E.,Shats-ts, V. D.,Zitsmane, I.,Purvinya, A.
, p. 1319 - 1327 (2007/10/02)
Substituted (piperidinoalkyl)silanes were synthesized and investigated by means of multinuclear NMR spectroscopy and GLC.The data obtained indicate an additional N-Si interaction in α-aminomethylsilanes that depends substantially on the properties of the substituents attached to the silicon atom.The effect of the R1R2R3Si substituent on the capacity of the nitrogen atom for intermolecular interactions is not restricted to steric effects but also has electronic character.
