Stereospecific photocycloaddition of electron-deficient arylalkenes to 9-cyanophenanthrene via exciplex
摘要:
Irradiation of benzene solutions containing 9-cyanophenanthrene and electron-deficient arylalkenes such as E- and Z-methyl cinnamates afforded (2pi + 2pi) photocycloadducts between the two electron-deficient components in a stereospecific manner.
顺式-肉桂腈1衍生的乙烯基碳负离子是通过在低温下在质子惰性溶剂中与二异丙基氨基化锂(LDA)作为碱反应而形成的;与各种亲电子试剂(E)的反应生成相应的衍生物PhCHC(E)CN。衍生自1的乙烯基碳负离子的构型稳定性和反应产物的几何形状受介质的溶剂化性能影响。在差的溶剂化介质-二乙醚-己烷(4:1)中保持构型。加入冠醚或使用THF作为溶剂,得到具有反式几何结构的产物。肉桂腈(顺式和反式)去质子化的部位。)与肉桂酸酯进行了比较并进行了讨论。根据产物的1 H NMR光谱确定其几何形状。
organolithiums, Grignardreagents, or zincates to sulfinylnitriles triggers a facile sulfinyl–metal exchange to afford N‐ or C‐metalated nitriles. Sulfinyl–magnesium exchange–alkylations efficiently install quaternary and tertiary centers, even in the case of tertiary sulfinylnitriles that contain a highly acidic methine proton. α‐Sulfinylalkenenitriles afford moderately nucleophilic magnesiated nitriles, and