作者:John L. Kice、Young-Hee Kang
DOI:10.1016/s0040-4020(01)96712-2
日期:1985.1
free-radical addition to allenes (R1CHCCR2R3) to afford the regioisomer R1CH(SePh)C(SO2Ar)CR2R3 (13) arising from addition of the p-tolylsulfonyl group to the central carbon of the allene and transfer of the phenylseleno group to the less highly substituted of the two terminal carbons. This regioselectivity, which contrasts with that observed in the majority of radical additions to allenes, can be explained
硒苯基p -tolueneselenosulfonate(1A)经历高度选择性,光引发的,自由基加成到丙二烯(R 1 CHCCR 2 - [R 3),得到区域异构体[R 1 CH(SEPH)C(SO 2 AR) p相加产生的CR 2 R 3(13)-甲苯基磺酰基至丙二烯的中心碳,并将苯基硒烯基转移至两个末端碳的取代度较低的基团。这种区域选择性与在大多数对烯丙基的自由基加成中观察到的区域选择性相反,可以通过参考Heiba提出的概念来解释,该概念对于确定对烯丙基的不同自由基加成中的取向很重要。将13中的PhSe基团氧化为PhSe(O),得到烯丙基亚硒酸酯,该序列容易进行,一致的[2,3]-σ重排,然后水解所得硒酸根,得到β-甲苯磺酰基取代的烯丙醇, [R 1 CHC(SO 2的Ar)C(OH)R 2 - [R 3(14)的收率为70–98%。的光加成1A到丙二烯,随后的转化13至14由