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.
Synthesis of isoindoloisoquinoline alkaloids. A revision of the structure of (±)-nuevamine
作者:Ricardo Alonso、Luis Castedo、Domingo Domínguez
DOI:10.1016/s0040-4039(00)98873-7
日期:1985.1
An easy and efficient method for the synthesis of isoindoloisoquinolines, and the assignment of a new structure for the alkaloid (±)-nuevamine are reported.
Multimetallic Iridium-Tin (Ir-Sn<sub>3</sub>) Catalyst in<i>N</i>-Acyliminium Ion Chemistry: Synthesis of 3-Substituted Isoindolinones<i>via</i>Intra- and Intermolecular Amidoalkylation Reaction
作者:Arnab Kumar Maity、Sujit Roy
DOI:10.1002/adsc.201400234
日期:2014.8.11
AbstractThe multimetallic iridium‐tritin (Ir‐Sn3) complex [Cp*Ir(SnCl3)2SnCl2(H2O)2}] (1) proved to be a highly effective catalyst towards COH bond activation of γ‐hydroxylactams, leading to a nucleophilic substitution reaction known as the α‐amidoalkylation reaction. Catalyst 1 can be easily synthesized from the reaction of (pentamethylcyclocyclopentadienyl)iridium dichloride dimer [Cp*IrCl2]2} and tin(II) dichloride (SnCl2). In terms of catalyst loading, reaction conditions and yields of the product formed, 1 is found to be superior compared to classical Lewis acid catalysts. Different carbon (arenes, heteroarenes, allyltrimethylsilane, 1,3‐dicarbonyls) and heteroatom (alcohols, thiols, amides and sulfonamides) nucleophiles have been successfully employed in the intramolecular and intermolecular alkylations, as well as in heterocyclization reactions. In the majority of cases good to excellent yields of 3‐substituted isoindolinones and 5‐substituted pyrrolidin‐2‐ones have been obtained. Besides, the reactions are also atom economical and salt free. It is proposed that the multimetallic Ir‐Sn3 catalyst behaves as a mild and selective Lewis acid to activate the γ‐hydroxylactam towards the formation of the N‐acyliminium ion; the latter being trapped by potent nucleophiles leading to the desired products.magnified image