90196-92-2Relevant articles and documents
Regioselectivity of the photochemical addition of ammonia, phosphine, and silane to olefinic and acetylenic nitriles
Guillemin, Jean-Claude,Breneman, Curt M.,Joseph, Jeffrey C.,Ferris, James P.
, p. 1074 - 1082 (2007/10/03)
An investigation of the regioselectivity and mechanisms of the photochemical addition of NH3, PH3, and SiH4 to olefinic and acetylenic nitriles is described. The photolysis of NH3 in the presence of acrylonitrile led to the α-addition product 2-aminopropanenitrile (2), propanenitrile, and 2,3-dimethylbutanedinitrile (3). When NH3 was photolyzed in the presence of substituted derivatives (crotononitrile, methacrylonitrile, or 1-cyclohexenecarbonitrile), the α-addition products were still obtained. However, under similar reaction conditions, only the β-addition products, 7 and 8, were obtained from acrylonitrile and PH3, or acrylonitrile and SiH4, respectively. On the other hand, the photolysis of 2-butynenitrile and NH3 gave the β-addition products, (Z)- and (E)-3-aminocrotononitrile (10). The photolysis of these acetylenic nitriles with PH3 or SiH4 also gave the β-adducts (12) and (13). The α-addition of NH3 proceeds by the stepwise addition of H· and ·NH2, respectively, to the α,β-unsaturated nitriles. The β-addition products are formed by a radical chain mechanism initiated by photochemically generated radicals. The radical chain pathway provides an explanation for a number of previously described photochemical additions to olefins and acetylenes. Photochemical processes similar to the addition of ammonia and phosphine to unsaturated organic compounds may have played a role in the evolution of the atmosphere of the primitive Earth, and may even be currently occurring in the atmospheres of other planets.
