Photolysis of Alkyl Aryl Sulfoxides: α-Cleavage, Hydrogen Abstraction, and Racemization1
摘要:
The photochemistry of a series of alkyl aryl sulfoxides is described. The initial event of the photolysis process is homolytic cleavage to form sulfinyl/alkyl radical pairs. The radical pair partitions between recombination to starting material, formation of sulfenic esters, disproportionation to an olefin and benzenesulfenic acid, and formation of typical radical escape products. The quantum yield for conversion depends on the structure or the reactivity of the alkyl radical, with the sequence benzyl > tertiary alkyl > secondary alkyl > primary alkyl > (di)aryl. The high racemization efficiency of some aryl primary-alkyl sulfoxides suggests that another nonradical pathway for the photoracemization process may exist. Product analysis does not support any hydrogen abstraction pathways.
描述了在良性反应条件下进行的AB(C 6 F 5)3 H 2 O催化的叔脂肪族氟化物的脱氟官能化。通过快速有效地形成一系列具有新安装的C(sp 3)N,S,C和O键的产品,可以举例说明该方法的综合用途。这项研究说明了其他惰性原料的广泛反应性,并提供了通往有价值的和合成上代表性不足的产品的途径,这些产品以前从未从此类氟化前体中获得。
作者:Alan R. Katritzky、Subbu Perumal、Wojciech Kuzmierkiewicz、Ping Lue、John V. Greenhill
DOI:10.1002/hlca.19910740829
日期:1991.12.11
tert- Alkyl sulfides are conveniently prepared from α-(1H-benzotriazol-1-yl)alkyl sulfides by displacement of the 1H-benzotriazol-1-yl group with Grignard reagents. The 1-[α-(alkylthio)alkyl]- and 1-[α-(arylthio)alkyl]-1H-benzotriazole intermediates are easily available by several routes: (i) displacement of the halogenfrom appropriate halides by sodium salts of thiols, (ii) condensation of 1H-benzotriazole