Allyl Allylamines, palladium-catalyzed

In 1993, Corriu et al. studied the synthesis of nitrogen-containing heterocycles from (Z)-3-(tribulylstannyl)allylamine, which was prepared by the reaction of Af-(trimethylsilyl)allylamine with 2 mol of ra-butyllithium followed by treatment with chlorotributyltin and subsequent hydrolysis. The unprotected (Z)-3-(tributylstannyl)allylamine underwent a palladium-catalyzed cross-coupling reaction with aromatic bromides affording a stereospecific preparation of substituted allylic amines with Z configuration of the carbon-carbon double bond. The reactions of o/t/zo-functionalized aryl bromides offer a one-step preparation of 7-membered nitrogen heterocycles in high yields (Scheme 4.18). 

Nonracemic, axially stereogenic allylamine 8 is obtained by palladium(0)-catalyzed allylic substitution of meso-diastereomers 7 with morpholine using (S,S)-Diop (D)62. From both substrates, the product 8 displays an optical rotation unequal to zero. The corresponding enantiomeric excess values have not been determined. 

Olefin isomerization catalyzed by ruthenium alkylidene complexes can be applied to the deprotection of allyl ethers, allyl amines, and synthesis of cyclic enol ethers by the sequential reaction of RCM and olefin isomerization. Treatment of 70 with allyl ether affords corresponding vinyl ether, which is subsequently converted into alcohol with an aqueous HCl solution (Eq. 12.37) [44]. In contrast, the allylic chain was substituted at the Cl position, and allyl ether 94 was converted to the corresponding homoallylic 95 (Eq. 12.38). The corresponding enamines were formed by the reaction of 70 with allylamines [44, 45]. Selective deprotection of the allylamines in the presence of allyl ethers by 69 has been observed (Eq. 12.39), which is comparable with the Jt-allyl palladium deallylation methodology. This selectivity was attributed to the ability of the lone pair of the nitrogen atom to conjugate with a new double bond of the enamine intermediate. 

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