Reactions of primary and secondary amines with fluoronitrene generated from isopropyl N,N-difluorocarbamate

A Simple and Efficient Synthesis of 1,6-Disubstituted 1,4,5,6-Tetrahydropyridazines by Ring Enlargement of 2,5-Dibenzotriazolyl-N-Aminopyrrolidines

“…1 H NMR spectra were recorded on a Varian VXR-300 spectrometer with TMS as an internal reference. 13 C NMR spectra were recorded at 75 MHz on the same instrument, using the middle peak of CDCl 3 ( δ = 77.0) as the reference. All reagents were purchased from chemical suppliers and used without further purification unless otherwise indicated.…”

“…4 Several routes exist for the preparation of 1,4,5,6-tetrahydropyridazines: (i) hydrazones, obtained by treatment of α,β -unsaturated ketones containing an activated methylene group with aryl diazonium salts according to the Japp-Klingemann procedure, undergo intramolecular ring closure into 1,4,5,6-tetrahydropyridazin-4-ones in fair to excellent yields; 5 (ii) analogously, reactions of hydrazine with γ -ketooxazoles in acidic conditions yielded fused tetrahydropyridazines, via hydrazone intermediates; 6 (iii) substituted tetrahydropyridazines have also been prepared from azoalkenes intermediates by intermolecular Diels-Alder reactions; 7 (iv) reaction of the appropriate ene-hydrazines with acetylenedicarboxylic esters; 8 (v) hydrogenation of pyridazine in the presence of hydrated ruthenium oxide; 9 (vi) thermal isomerisation of cis -3,6-diphenyl-3,4,5,6-tetrahydropyridazine; 10 and (vii) reaction of hydrazines with 2,5-dimethoxytetrahydrofuran in the presence of sodium borohydride in acidic conditions. 11 Reported ring enlargement routes to 1,4,5,6-tetrahydropyridazines proceed from 4,5-dihydropyrazoles, 12 pyrrolidines 13 and especially from 1-aminopyrrolidines 14 via diazene intermediates. These afford 1,4,5,6-tetrahydropyridazines in average to good yields (40-70%) but require a multi-step synthesis of the 1-aminopyrrolidine substrates and are restricted to unsubstituted amino groups.…”

Reductive Deamination by Benzyne for Deoxy Sugar Synthesis Through a Domino Reaction

“…Representative examples include hydrogen peroxide, molecular oxygen, nitrous anhydride, nitrosyl tetrafluoroborate, pyridoxal phosphate, and zinc dichromate trihydrate . Close scrutiny of the literature reveals that only a limited number of reagents are used to accomplish “reductive deamination.” Reagents for this type of reaction include isopropyl N , N ‐difluorocarbamate, samarium iodide, and sodium borohydride …”

“…Deamination, the removal of an amine group from a molecule, plays an important role in chemical transformations and biological systems . Chemical reagents developed for this purpose include copper(II) halides along with alkyl nitrites; HCO 2 H/acetic anhydride (Ac 2 O) followed by POCl 3 /Et 3 N and then tributyltin hydride; hydrogen peroxide along with tetrabutylammonium iodide as the catalyst; isopropyl N , N ‐difluorocarbamate; nitrosyl acetate; nitrosyl tetrafluoroborate; p ‐nitrophenyl formate, Ac 2 O, POCl 3 /Et 3 N, and tributyltin hydride in sequence; samarium iodide; sodium borohydride along with 2,3,5,6‐tetraphenylpyrylium tetrafluoroborate; sodium nitrite; and zinc dichromate trihydrate . Deamination of amino acids and proteins can proceed through an oxidative process by using molecular oxygen in the presence of a d ‐amino acid oxidase, lysine cyclodeaminase, l ‐lysine oxidase, pyridoxal phosphate cofactor, and so forth.…”

“…[2] Close scrutiny of the literature reveals that only al imited number of reagents are used to accomplish "reductive deamination." Reagents for this type of reactioni nclude isopropyl N,N-difluorocarbamate, [6] samarium iodide, [11] and sodium borohydride. [12] The reactive benzyne species [21] is considered by us as an ideal candidate for reductive deaminationf or two reasons.…”