A Convenient Synthesis of Indole-Substituted 2-Pyrrolidones and Their Cyclized Derivatives

Abstract

Condensation between indole, Meldrum’s acid, and benzyloxycarbonylacetaldehyde or aminoacetaldehyde derivatives yielded trimolecular adducts 7a−c. The latter were cyclized to indole‐substituted 2‐pyrrolidones 15a−b or 3‐aminopyrrolid‐2‐ones 18a−b, depending on the starting material. Derivative 18a was transformed into pyrrolo[3′,4′:5,6]pyrido[3,4‐b]indol‐3(2H)‐ones 19a and 20a by a Pictet−Spengler condensation with benzaldehyde.

Indole based multicomponent reactions towards functionalized heterocycles

“…In a preliminary study, 35 the trimolecular adducts 49 were prepared by using Cbz (CO 2 Bn) masked 2-hydroxy-48a or 2-aminoacetaldehydes 48b,c as aldehyde partners (Scheme 14). Deprotection of 49 and subsequent internal nucleophilic attack allowed the isolation of furanone 50a (90 %), and pyrrolidinone 50b (80 %), as sole products.…”

A one-pot chemoselective synthesis of secondary amines by using a biomimetic electrocatalytic system

“…The carbon type [methyl, methylene, methide or quaternary (noted Cq)] was determined by DEPT experiments. The identity of known secondary amines A and C (Scheme 3) as well as that of known vicinal diamines B (Scheme 3) was confirmed by 1 H and 13 C NMR after comparison with previously reported data: dibenzylamine [23], N-benzyl-N-cyclopropylmethylamine (entry 1, Table 1) [24]; N-benzyl-N-cyclohexylmethylamine (entry 2, Table 1) [25]; N-benzyl-Ncyclohexylamine (entry 3, Table 1) [26]; N-benzyl (3,3-dimethyl)butylamine (entry 5, Table 1) [27]; N-benzylhexylamine (entry 6, Table 1) [27,28]; N-benzyl-1-phenyl-2-propylamine (entry 7, Table 1) [29]; N,N-di(2-methoxyethyl)-1,2-bisphenylethane-1,2-diamine (entry 8, Table 1) [30], benzyl(2,2-dimethoxyethyl)amine (entry 9, Table 1) [31]; 2benzylaminoethanol (entry 10, Table 1) [32]; N,N-bis-(p-fluorobenzyl)amine (entry 1, Table…”

On the choice of Lewis acids for the Prins reaction; two total syntheses of (±)-Civet

“…Mp 43 C (lit. 55 A stirred solution of (E)-dibenzylhex-3-enedioate (2.70 g, 8.33 mmol) in CH 2 Cl 2 (150 ml, 18 ml/ mmol) was cooled to À78 C using an acetone/cardice bath. O 3 (flow rate 70, voltage 200V) was bubbled through the solution for half an hour, after which the solution turned blue.…”