87166-93-6

Upstream product

• 134612-93-4 N-Pent-4-enyl-benzimidic acid 2-thioxo-2H-pyridin-1-yl ester 
• 5724-81-2 1-pyrroline 
• 2728-04-3 N,N-diethyl-ortho-toluamide 
• 1404376-10-8 5-azido-2-benzylpentanoic acid 
• 690256-02-1 2-(3-bromo-propyl)-2H-isoquinolin-1-one 
• 1666-13-3 diphenyl diselenide 

Relevant academic research and scientific papers

α-C-H/N-H Annulation of Alicyclic Amines via Transient Imines: Preparation of Polycyclic Lactams

Polycyclic lactams are prepared in a single operation from o-toluamides and cyclic amines in a process that involves transient cyclic imines, species that are conveniently obtained in situ from the corresponding lithium amides and simple ketone oxidants. Imines thus generated, such as 1-pyrroline and 1-piperideine, engage lithiated o-toluamides in a facile annulation process. Undesired side reactions such as imine deprotonation and o-toluamide dimerization are suppressed through the judicious choice of reaction conditions.

Tf2O-Promoted Intramolecular Schmidt Reaction of the ω-Azido Carboxylic Acids

A designed Tf2O-promoted intramolecular Schmidt reaction of 2-substituted ω-azido carboxylic acids was demonstrated. Tf2O was used as an activation reagent for the carboxylic acid, and ω-azido anhydride was in situ generated, releasing a molecular TfOH, which acted as an acid promoter for the Schmidt process. A series of 2-substituted pyrrolidines was produced and acetylated for better purification. The strategy was also efficient for conversion of a 4-substituted ω-azido carboxylic acid to the tricyclic lactam.

Radical cyclizations to quinolone and isoquinolone systems under oxidative and reductive conditions

Radical cyclizations to quinolone and isoquinolone systems under Fenton-type and n-Bu3SnH-mediated conditions are described. For N-iodoalkylquinolones, ca. 3:1 mixtures of oxidative cyclization products at C-2, and unexpectedly at C-8, were obtained under both conditions. Five- or six-membered oxidative cyclization products were obtained from N-iodoalkylisoquinolones under Fenton-type conditions, whereas n-Bu 3SnH-mediated reactions gave products of reductive cyclization in the five, six, and seven-membered series.

Chemistry of Amidyl Radicals Produced from N-Hydroxypyridine-2-thione Imidate Esters

The title radicals precursors were prepared from secondary amides by reaction of the amide with phosgene to give an imidoyl chloride followed by reaction with the sodium salt of N-hydroxypyridine-2-thione.Visible light initiated reactions of these precursors gave amidyl radicals 2 which could react with their precursors to give N-(2-pyridylthio) amides or with t-BuSH to give the parent amide.Radicals 2 containing δ,ε-unsaturation on the acyl or alkyl chain cyclized in a 5-exo fashion to give ultimately γ-lactams and N-acylpyrrolidines, respectively.Tandem 5-exo cyclizations of the N-allyl-4-pentenamidyl radical gave pyrrolizidinone products, and a tandem 5-exo/6-endo reaction sequence of the N-(4-pentenyl)benzamidyl radical gave, ultimately, 3,4-benzoindolizidinone.Several relative rate constants for cyclization and trapping of the amidyl radicals and for intramolecular reactions and trapping of the carbon-centered radicals formed by amidyl radical cyclizations were determined, and these values can be employed in synthetic planning.

FACILE PRODUCTION AND CYCLIZATIONS OF AMIDYL RADICALS

Amides were converted via imidoyl chlorides into N-hydroxypyridine-2-thione imidate esters that were precursors for amidyl radicals; amidyl radicals containing δ,ε-unsaturation cyclized in a 5-exo fashion.