Reactions of α-difluoro azides with olefins

Abstract

Reactions of α difluoro azides with olefins result in oxidative fluoroamination or amination of the C=C bond.

Synthesis, Stability and Reactivity of α‐Fluorinated Azidoalkanes

“…[13] When the reactions are performed under hydrolysis conditions by silica gel, fluorinated amides form (Scheme 23). [31] Cyclohexene, an unstrained cyclic alkene, reacts with af luorinateda zide at much harsher conditions to afford products of oxidative amination and aminofluorination (Scheme 24). [31] Althought he reaction of the same azide with styrene leads to polymerization, the use of trans-stilbeneg ives am ixture of two isomeric enamides (Scheme 25).…”

“…[31] Althought he reaction of the same azide with styrene leads to polymerization, the use of trans-stilbeneg ives am ixture of two isomeric enamides (Scheme 25). [31] Scheme18. Synthesis of a,a-difluoroazides from dithianyliumt riflates.…”

“…[13] Anthracene reacts with 1-azido-1,1,2,3,3,3-hexafluoropropane at 180 8Ct oa fford amide 14 (Scheme 38). [31] 4. AB rief Note on b-, g-and d-Fluorinated Azidoalkanes Alkyl azides substituted with fluorine atoms in b-, gor d-positions are readily preparedb yS N 2r eactions starting from sodium azide and the corresponding triflates,m esylates, tosylates or iodides (Scheme 39).…”

“…Simple alkenes react very slowly with α‐fluorinated azidoalkanes, but strained alkenes such as norbornene react readily in [3+2] cycloaddition reactions to triazoline products, which undergo further reactions by the loss of nitrogen, rearrangement and HF elimination (Scheme ) . When the reactions are performed under hydrolysis conditions by silica gel, fluorinated amides form (Scheme ) …”

Divergent Reaction Mechanisms in the Aminofluorination of Alkenes

“…[31] In an analogous manner, but with allenes as unsaturated precursors, monofluoro pyrrolidines could be prepared in moderate the product resulting from a competitive oxidative amination of the olefin in a 1:1 ratio (Scheme 9). [37] The azide reacts with the double bond and upon N 2 release, an aziridine is formed. Upon Frelease, an α-fluoroiminium cation is generated and trapped by the fluoride in a S N 2 reaction.…”