The [2+2] cycloaddition vs. substitution in photochemical reactions of methoxybenzene-acrylonitrile systems was written by Ohashi, Mamoru;Tanaka, Yoshio;Yamada, Shuzo. And the article was included in Tetrahedron Letters in 1977.SDS of cas: 5351-07-5 This article mentions the following:
Irradiation of PhOMe and RCH:CR1CN (I; R, R1 = H, Me) in MeCN gave the corresponding [2+2]cycloadducts II, whereas irradiation of PhOMe and I (R, R1 = H, Me) in MeOH gave substitution products in addition to II. Thus the photochem. reactions of I (R, R1 = H, Me) with PhOMe in MeCN are similar to those of I (R = R1 = H) with PhOMe in MeCN (O. et al., 1976) whereas the reactions in MeOH differ, since I (R = R1 = H) gave only substitution products, the amount decreasing in the order I (R = R1 = H) > I (R = H, R1 = Me) > I (R = Me, R1 = H). A similar tendency is also observed for (MeO)2C6H4-RCH:CR1CN systems. The higher the reduction potential (or electron affinity) of the olefin or the lower the oxidation potential of the aromatic, the larger the amount of substitution products. Although participation of the proton-transfer step is revealed by the use of MeOD in place of MeOH, the rate-determining step of the substitution is electron transfer. A reaction scheme consistent with these results is given. In the experiment, the researchers used many compounds, for example, 2-(4-Methoxyphenyl)-2-methylpropanenitrile (cas: 5351-07-5SDS of cas: 5351-07-5).
2-(4-Methoxyphenyl)-2-methylpropanenitrile (cas: 5351-07-5) belongs to nitriles. Nitriles are polar, as indicated by high dipole moments. As liquids, they have high relative permittivities, often in the 30s. Nitriles are susceptible to hydrogenation over diverse metal catalysts. The reaction can afford either the primary amine (RCH2NH2) or the tertiary amine ((RCH2)3N), depending on conditions.SDS of cas: 5351-07-5
Referemce:
Nitrile – Wikipedia,
Nitriles – Chemistry LibreTexts