High regioselectivity in electrochemical α-methoxylation of N-protected cyclic amines
摘要:
N-Protecting groups of alpha-substituted cyclic amines strongly affected the regioselectivity in electrochemical methoxylation of these compounds. Namely, N-acyl derivatives were transformed into alpha'-methoxylated compounds, while N-cyano derivatives changed into alpha-methoxylated derivatives. Furthermore, Lewis acid catalyzed nucleophilic substitution of the alpha-methoxylated compounds protected with cyano group afforded alpha,alpha-disubstituted cyclic amines. (c) 2008 Elsevier Ltd. All rights reserved.
作者:Liliana Boiaryna、Mohamed Kamal El Mkaddem、Catherine Taillier、Vincent Dalla、Mohamed Othman
DOI:10.1002/chem.201202225
日期:2012.10.29
applied in cascade‐type reactions for the synthesis of different nitrogen‐based compounds. The reactions likely proceed by a new gold‐catalyzed cascade intermolecular α‐amidoalkylation/intramolecular carbocyclization cascade process by unifying both the σ‐ and π‐Lewisacid properties of the gold salts. In the first part of this report we show that the σ‐Lewis acidity of gold(I) and gold(III) could be
N-Acyliminium Ion Chemistry: Highly Efficient and Versatile Carbon-Carbon Bond Formation by Nucleophilic Substitution of Hydroxy Groups Catalyzed by Sn(NTf2)4
作者:Raja Ben Othman、Radouane Affani、Marie-José Tranchant、Sylvain Antoniotti、Vincent Dalla、Elisabet Duñach
DOI:10.1002/anie.200906036
日期:2010.1.18
O‐acetals are used in a catalytic, highlyefficient α‐amidoalkylation of a broad range of carbon‐centered nucleophiles, including silicon‐based components, active methylene derivatives, electron‐rich arenes, and even simple ketones (see scheme). The reactions proceed in a highlyefficient manner and typically require only 1 mol % of the Lewis superacidic reagent Sn(NTf2)4 as the catalyst.
Electrochemical Deallylation of α-Allyl Cyclic Amines and Synthesis of Optically Active Quaternary Cyclic Amino Acids
作者:Peter G. Kirira、Masami Kuriyama、Osamu Onomura
DOI:10.1002/chem.200903512
日期:2010.4.6
Electrochemical oxidation of α‐allylated and α‐benzylated N‐acylated cyclic amines by using a graphite anode easily affords the corresponding α‐methoxylated products with up to 76 % yield. Ease of oxidation was affected by the type of electrode, the size of cyclic amine, and the nature of the protecting group. This method was successfully applied to the synthesis of optically active N‐acylated α‐alkyl‐α‐amino
fragmentation of primaryalkoxylradicals is usually a minor process with respect to hydrogen abstraction and other competing reactions. However, when β-aminoalcohols were used as substrates, the scission proceeded in good to excellent yields and no side reactions were observed. The fragmentation can be coupled with an allylation or alkylation reaction, to give alkaloidanalogues and functionalized
Light-driven radical-polar crossover catalysis for cross-coupling with organosilanes
作者:Tomotoki Matsuo、Kazunori Nagao、Hirohisa Ohmiya
DOI:10.1016/j.tetlet.2022.154231
日期:2022.12
enabling the cross-couplingbetween aliphatic carboxylic acid-derived redox active esters and organosilanes. In this protocol, a carbocation equivalent generated from the redox active ester by radical-polar crossover process could react with an organosilane reagent. This protocol allows to forge C(sp3)–C(sp3), C(sp3)–C(sp2) and C(sp3)–C(sp) bonds under transition-metal free and mild reaction conditions