Intramolecular 1,3‐Cl/H Exchange in F₃CCCI₂N(CH₃)₂ and Cl₃CCCl₂N(CH₃)₂

CF3-substituted carbocations: underexploited intermediates with great potential in modern synthetic chemistry

“…Viehe et al also contributed by developing the chloroalkylamino reagent 199 , bearing a geminal CF 3 group, which proved to be a valuable synthon for the introduction of the CF 3 group into molecules [ 125 ]. Thus, 199 exhibits a high reactivity towards many functionalities, as depicted below ( Scheme 49 ).…”

Synthesis of Iminium Salts, Orthoesters and Related Compounds

“…155 (35) X=O.s OSOCI H-<.+ Cl NRIR2 (34) Cl H-<.+ Cl + S02 (20) NRIR2 (21) R1=H,X=O (iv) Miscellaneous reagents A very efficient preparation of amide chlorides comprises the action of elemental chlorine on thioamides in CH2Ch or CCI4; even amide chlorides which possess electron-attracting substituents in the a-position have been prepared in this way. 7,9,143,156 DMF was converted to the corresponding iminium salt (27) by the following reagents: 5 perfluorobutyryl chloride, 2,2-dichlorobenzodioxole (36) and 2,2,2-trichlorobenzodioxaphosphole (37). (36) (37) (i) Hydrogen halides to nitriles or imidoyl halides…”

Cobalt-Induced C−N and C−C Bond Formation via Metal-Stabilized α-CF3 Carbenium Ion

“…In most cases they are stabilized by adjacent electron donor substituents such as aryl groups or heteroatoms . In some rare cases they are sufficiently stabilized, for example by two electron-donating substituents, to be observable by NMR spectroscopy or in the gas phase …”