Generation of C₂F₅CHN₂ In Situ and Its First Reaction: [3+2] Cycloaddition with Alkenes

Abstract

The novel chemical reagent, C2 F5 CHN2 , is generated in situ from C2 F5 CH2 NH2 ⋅HCl and sodium nitrite. It reacts with mono- and disubstituted electron-deficient alkenes at room temperature to afford C2 F5 -pyrazolines in excellent yields.

Traditional and New methods for the Preparation of Diazocarbonyl Compounds

“…Over the years, a methodology based on a primary amine and a nitrosating agent to perform diazo syntheses has been expanded to fluorinated diazoalkanes and monofluorosubstituted diazoalkanes (Mykhailiuk 2014(Mykhailiuk , 2015(Mykhailiuk , 2017. For example, a novel chemical reagent, heptafluoroisopropyl diazomethane (i-C 3 F 7 CHN 2 ), which has been generated in situ, can react with electron-deficient alkyl groups and polyfluoro pyrazoles (Mykhailiuk 2017) ( Figure 31…”

Three-component synthesis of C2F5-substituted pyrazoles from C2F5CH2NH2·HCl, NaNO2 and electron-deficient alkynes

“…This method worked for both the mono- and disubstituted alkynes. Because of similar electronic properties of CF 3 and C 2 F 5 groups [ 1 ], it was supposed that a reaction between in situ generated C 2 F 5 CHN 2 [ 47 ], and electron-deficient alkynes would lead to C 2 F 5 -pyrazoles. In this work, this hypothesis was proven; the scope and selectivity of this transformation was studied and the high practical potential of the developed method is shown.…”

Fluoroalkyl‐Substituted Diazomethanes and Their Application in a General Synthesis of Pyrazoles and Pyrazolines

“…Recently, the synthesis of trifluoromethyl diazomethane from primary amines has been reported . Morandi and Carreira reported on the utilization of inorganic nitrites for the preparation of trifluoromethyl diazomethane and applications in cyclopropanation reactions .…”

“…The synthetic applicability of trifluoromethyl diazomethane was further investigated in the past years by different research groups, for example in cyclopropanation, and cycloaddition reactions ,. Recently, Mykhailiuk reported a new strategy for the preparation of these versatile reagents using an organic nitrite for the acid‐catalyzed synthesis of difluoromethyldiazomethane and its application in [2+3] cycloaddition reactions . Yet, a generally applicable method for the simple preparation of fluoroalkyl‐substituted diazomethanes and their application to organic synthesis is still highly desired.…”