α-Nitrothiocyanates R2C(SCN)NO2 have been prepared by oxidative addition of thiocyanate anion to nitronate anions and undergo SRN1 substitution reactions by loss of thiocyanate with nitronate anions, phenylsulfinate, azide and p-nitro- and p-chloro-benzenethiolates in dipolar aprotic solvents. 2-Nitro-2-thiocyanatopropane and other 2-substituted-2-nitropropanes [Me2C(X)NO2 with X = I, Br, Cl, NO2, PhSO2] react with thiolates by SRN1 reactions and/or redox reactions to give disulfides by a polar abstraction or chain SET (SET2) mechanisms. The products are dependent on the nucleophilicity of the thiolates, the polarisability of the α-substituent, the solvent and the presence of light catalysis, radical traps or strong electron acceptors. 2-Substituted-2-nitropropanes [Me2C(X)NO2 with X = N3,
NO2, CN, p-NO2âC6H4âNN] undergo SRN1 substitutions with thiolates by loss of nitrite. 2-Substituted-2-nitropropanes Me2C(X)NO2 and thiolates only yield disulfides in methanol due to solvation of the nitro groups.
α-亚硝基
硫氰酸酯R2C(SCN)
NO2通过
硫氰酸根离子对
亚硝酸根离子的氧化加成制备,并在非质子性偶极溶剂中通过失去
硫氰酸盐与
亚硝酸根离子、
苯磺酸盐、
叠氮化物以及对硝基和对
氯苯硫醇盐发生SRN1取代反应。2-硝基-2-
硫氰酸丙烷和其他2-取代-
2-硝基丙烷[Me2C(X) ,其中X=I、Br、Cl、 、PhSO2]通过SRN1反应和/或氧化还原反应与
硫醇盐反应,通过极性提取或链
SET(
SET2)机制生成二
硫化物。产物取决于
硫醇盐的亲核性、α-取代基的极化性、溶剂以及光催化、自由基捕获剂或强电子受体的存在。2-取代-
2-硝基丙烷[Me2C(X) ,其中X=N3、 、CN、p- -
C6H4-NN]在与
硫醇盐失去
亚硝酸盐的情况下发生SRN1取代。2-取代-
2-硝基丙烷Me2C(X) 和
硫醇盐仅在
甲醇中由于硝基团的溶剂化而产生二
硫化物。