Electroreductive Coupling of Aromatic Imines with Electrophiles in the Presence of Chlorotrimethylsilane

Abstract

Electroreduction of aromatic imines in the presence of electrophiles gave the corresponding inter- and intramolecular coupling products when the reaction was carried out with the use of chlorotrimethylsilane (CTMS) as the trapping agent of an anion intermediate.

Simple electrochemical reduction of nitrones to amines

“…An equimolecular mixture of CH 3 CN and EtOH gave a complex mixture with no formation of the amine (Entry 4), whereas the use of CH 3 CN with another protic solvent such as water was found as optimal (Entry 5). In an electrochemical process for a radical addition of imines to acrylates, the use of triethylamine proved to be efficient to increase the adduct yields 15. When using NEt 3 as additive the yield increased up to 42% (Entry 6).…”

N–H insertion reactions of rhodium carbenoids. Part 1. Preparation of α-amino acid and α-aminophosphonic acid derivatives

“…A stirred solution of methyl 2-diazo-2-phenylacetate 1 (200 mg, 1.13 mmol) and 4-methoxyaniline (280 mg, 2.3 mmol) in dry dichloromethane ( 5 ml) was treated with rhodium(I1) acetate (2 moW). The mixture was heated under reflux for 12 h, the solvent evaporated and the residue chromatographed on silica gel (light petroleum-ether; gradient elution) to give the title compound (243 mg, 79%) as a colourless crystalline solid, mp 107-108°C (lit., 79 (8), 168 (9), 151 (5), 134 (8), 122 (7), 107 (6), 91 (7), 77 (1 l), 64 (6), 51 (6) and 39 (4).…”

Use of Electrochemistry in the Synthesis of Heterocyclic Structures

“…Shono, Kise, and co-workers reported that electroreduction is a powerful tool for the reductive coupling of aromatic imines with a variety of carbonyl compounds. 45 In the course of their studies on electroreductive couplings, in 2003, Kise and co-workers reported that intramolecular electroreductive coupling of chiral α-imino esters led to functionalized azetidines (Scheme 28). 46 In the presence of chlorotrimethylsilane (CTMS), electrolyzing imino esters 94 in a divided cell equipped with a Pt cathode and a Pt anode under a constant current at 100 mA gave azetidines 95 as single stereoisomers with 85−99% ee values.…”