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.
Catalytic Asymmetric Additions of Enol Silanes to In Situ Generated Cyclic, Aliphatic
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‐Acyliminium Ions
作者:Oleg Grossmann、Rajat Maji、Miles H. Aukland、Sunggi Lee、Benjamin List
DOI:10.1002/anie.202115036
日期:2022.2.21
Saturated nitrogen heterocycles are essential pharmacophores in drugs and natural products, and general methods for their enantioselective synthesis are still highly sought after. A new direct approach utilizing hemiaminal methyl ethers as N-acyliminium precursors for the enantioselective preparation of cyclic, aliphatic and 2-subsituted pyrrolidines, piperidines and azepanes has been achieved.
Original phosphorodithioic acid diesters were prepared according to an improvedsynthesis of 3,3′-disubstituted H8-BINOL derivatives. In preliminary experiments, these new Brønsted acids were tested as organocatalysts in three reactions. They promoted the Nazarov cyclisation with mixed selectivities, the Mannich reaction with good enantioselectivity and they catalyzed efficiently the alkylation of
Eco-friendly N-acyliminium ion chemistry: solvent-free HNTf2 and TIPSOTf-catalyzed α-amidoalkylation of silicon-based π-nucleophiles
作者:Marie-José Tranchant、Charlotte Moine、Raja Ben Othman、Till Bousquet、Mohamed Othman、Vincent Dalla
DOI:10.1016/j.tetlet.2006.04.090
日期:2006.6
The alpha-amidoalkylation of silicon-based pi-nucleophiles is efficiently catalyzed by HNTf2 or TIPSOTf at very low levels of loading in neat conditions. (c) 2006 Elsevier Ltd. All rights reserved.