Science of Synthesis

Feng, J. Q.; Li, C.-J., Science of Synthesis, (2009) 40, 606.

Another elegant amination procedure for the formation of allylamines from allylic alcohols involves the [3,3]-sigmatropic rearrangement of allylic trichloroacetimidates ‌86‌ into allylic amides ‌87‌ (the Overman rearrangement) by heating them in xylene at reflux (‌Scheme 31‌). The products can then be hydrolyzed to the desired amines [‌111‌,‌112‌] The yields obtained are generally good for reactions giving primary and secondary amides, but low for products where the amide nitrogen is bound to a tertiary carbon atom (10–40%). The hydrolysis of the amides is quite slow and stirring for 30 hours in 3 M sodium hydroxide in water and ethanol is necessary. The sigmatropic rearrangement may also be carried out at ambient temperature if a catalytic amount of mercury(II) trifluoroacetate is added and yields, and selectivities are comparable to those of the thermal reactions.[‌111‌,‌112‌] A two-step mechanism is proposed for the catalyzed reactions, so that an electrophilic addition of a mercury(II) ion to the double bond forms a cation, which is then captured intramolecularly by the nucleophilic imino nitrogen atom.[‌111‌] Even though the relatively high basicity of the imidates means that only a few metals are able to catalyze the type of rearrangement shown in ‌Scheme 31‌,[‌113‌] some soluble palladium(II) complexes are quite effective. However, ligand variety is reduced as phosphines inhibit the reaction.[‌114‌,‌115‌] This inhibitory effect probably arises because the strong electron-donating ability of a phosphine ligand diminishes the Lewis acid character of any palladium(II) complex that contains it.

‌Meeeee 88‌ Mee-Mee-Meee Meeeeeeeeeeee ee Meeeeee Meeeeeeeeeeeeeeeeeeee[‌888‌,‌888‌]

Me ee eeeeeee ee eeeeeee ee eeeeeeeeeeeeeeee eeeeeee ee eee eeeeeeee, ee Meeeeee eeeeeeeeeeeee ee eee eeeeeee ‌88‌ eee eeee eeeeeee eee eeeee eee eeeeeeeee eeeeeeeee ee eee eeeeee eeeeeee ‌88‌. Meee eeeeeeeee eeeee eee eeeeeeeeeee eeeee ‌88‌ ee 88% eeeee, eee ee 88% eeeeeeeeeeee eeeeee, eeee eeeeeeeeeeeeeee ee eee eeeeeee (‌Meeeee 88‌). Mee eee ee eeeeeeeeeeee ee eeeeeeeeee ee eeeeeee eeee eeeee e eeeeeee eeeeee ee eeeeeeeeeeeeee eeeeeee, eee eeee eee eeeeeeeeeeeee ee eeeeeeeee ee eeeeeeeeeeeeeeeee eee eeeeeeeeeeee eeeeee eeeee ee 88%.[‌888‌]

‌Meeeee 88‌ Me Meeeeeeeeeeeeeee Mee-Mee-Meee Meeeeeeeeeeee[‌888‌]

Meee eeeeee eee eeeeeeeeeeeeeeee eeeeeeee eeee eeeeeeeee ee eeeee eeeeeeeeee, e eeeeeee eeee eee eeeeeeee ee eee eeeeeeee eeeeeeee eeeeeee, eee eee eeee eeeeee eee eeeeeeeeeeeeee ee eeee eeeee eeeeeee M-eeeeeeeeeeeeeeeeeee ‌88‌ eeeeeeeee ee eeeeeeeee(MM) eeeeeeee eeee eeee eeeeeeeeeeee (‌Meeeee 88‌). Mee eeeeee, eeeeeeeeeeeee, eee eeeee ee eeeeeeee eee eee eeeeeeeee ee eee eeeeeee eeeeeeeeeeee ‌88‌ eee eeeeee eeee eeeee eeeeeeee ee eee eeeeeee eeeeeeeeee, eee eeee e eeeeeeeeeeeee eeeeee e eeeeeeee eeeee eeeeeeee eeee.[‌888‌] Me ee eeeeeee eeee eee eeeeeeeeee eeeee eeeeeee eeeeeeeeeeee eeeeee ee eeeeeeee eeeee eeeeeee eeeeeeeeee ee ee 88% ee eee eeeeeee eeeeeeee eee eeeeee ee eee eeeeeeee ee eee eeeeeeeee(MM) eeeeeeee. Meee ee eeeeeeeee eee eee eeeeee eeeeeeeeeee ee ee eeeeeeeeee eeeeeee ee eee eeeeeeee[‌888‌] eee eeee eee eeeeeeeeee eee eeeeeeeee eeeeeeeee.[‌888‌]

‌Meeeee 88‌ Mee-Mee-Meee Meeeeeeeeeeee ee Meeeeee M-Meeeeeeeeeeeeeeeeee[‌888‌]

Mee eeeeeeeee(MM)-eeeeeeeee eeeeeeeeeeeee ee eeeeee eeeeeee eeeeeeee ee eeeeee eeeeeee eeeeee eee eeee eeee eeeeeee, eee eeeeeeee eeee eee eeeeeee M-eeeeeeeeeeeeee. Meee, ee eee ee eeeeeee ee eee eeeeee eeeeeee ‌88‌, eeeee, ee eee eeeeeeee ee eee(eeeeeeeeeeee)eeeeeeeeeeeeeeeee(MM), eeeeeeeeee ee eee eeeeee ‌88‌, e eeeeeeeee ee (M)-M-(eeeeeeeeeeeeeee)eeeeeeeeeee (‌88‌) (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Me Mee-Mee-Meee Meeeeeeeeeeee ee ee Meeeeee Meeeeee[‌888‌]

Mee Meeeeee eeeeeeeeeeeee eee eeee eeee eeeeeee ee eeee eeeee eeeeeeeeee eee ee eeeeeee eeeeeeeeeee ee eeee eeeeeeee ee eeee ee e eeeeeeeee ee eeeeeeeeeeeeee (‌88‌) (‌Meeeee 88‌).[‌888‌]

‌Meeeee 88‌ Me Mee-Mee-Meee Meeeeeeeeeeee Meeeeeee ee eee Meeeeeeee ee Meeeeeeeeeeeee[‌888‌]

References

Meeeeee Meeeeeeeeee

• 8.Meeeee-Meee, (8888) M 8-8, 8888.
• 8.Meeeee-Meee, (8888) M 88e, 8888.
• 8.Meeeee-Meee, (8888) M 88e, 8888.
• 8.Meeeee-Meee, (8888) M 88e8, 888.