Benzyl chloride reaction with methyl acrylate

Benzyl chlorides are reactive partners of HR. For example, intra- and intermolec-ular reactions of the benzyl chloride 78 with methyl acrylate afford the indane ester 79 [52]. 

Benzyl chloride reacts easily with methyl acrylate in the presence of tri-n-butylamine and palladium acetate (1 mol %) as catalyst.51 The product is a mixture of (E)-methyl 4-phenyl-3-butenoate (67%) and (E)-methyl 4-phenyl-2-butenoate (9%), arising from elimination-addition reactions of the palladium hydride group which largely isomerize the initial elimination product. 

The reaction of benzyl chloride with metallic nickel in the presence of methyl acrylate was carried out at 85°C, and the expected addition product methyl 4-phenylbutanoate was formed in 17% yield (Equation 7.12). The reaction with acrylonitrile gave 4-phenylbutanenitrile in 14% yield together with cis- and tra 5-4-phenyl-2-butenenitriles, 4-cyano-6-phenylhexanenitrile, and 2-ben-zyl-4-phenylbutanenitrile (Equation 7.13). The results suggest the presence of a benzylnickel(II) chloride complex (1), which could have been formed by the oxidative addition of benzyl chloride to the metallic nickel (Scheme 7.7). The complex (I) would then be expected to add to the electron-deficient olefins, affording the addition product (111) via intermediate complex (IV). The formation of cis- and tra s-4-phenyl-2-butenenitrile (V) is reasonably explained by the reductive elimination of nickel hydride from intermediate (IV), which is analogous to the substitution reaction of olefins with alkylpalladium compound [158] and to the addition-elimination reaction of bis(triphenylphosphine) phenylnickel(II) bromide with methyl acrylate to yield methyl cinnamate [130]. Furthermore, intermediate (IV) seems to add another molecule of acrylonitrile to give the 1 2 adduct 4-cyano-6-phenylhexanenitrile (VI). 2-Benzyl-4-phenylbutanenitrile (VIII) would be formed by the metathesis of complex IV and the benzylnickel chloride (I). 

The smino acids used hy Blicke and Gould -were all secondary amines obtained by the addition of benzylamiue or alkyl amines to atropic acid or other substituted acrylic acids. The acid chloride salts v ore prepared by treatment with thionyl chloride, and after removing by-products the crude products were r cxed in bensene solution with excess dimethylaniline. The 1.8- and 1,4-disuhstituted azetidinones were isolated in yields of 40 80%, The benefioial influenoe of substitution was observed with the l-benzyl-S-methyl 4-phenyl- and l-benxyl-.S,3-dim thyl-4 phenyl-2-azetidinones, both of which were obtained in 90% yield. In an unsbooeasfu) attempt to prepare -aminodiasoketonea several of the acid chloride hydrochlorides were treated with diaxo-methane this reaction also fumishes the /9-laotams, although in rather low yield. 

---