1-芳基-2,2-二卤代乙酮肟与四氮化四硫(S 4 N 4)的反应:合成3-芳基-4-卤代-1,2,5-噻二唑的一般方法
摘要:
1-芳基-2,2-二氯-7、1-芳基-2,2-二溴-8、1-芳基-2-溴-2-氟-9和1-芳基-2-氯-2-氟-通过在室温下在EtOH中使相应的酮与盐酸羟胺反应来制备乙酮肟10。在1 H NMR光谱证据和1-(3-氯苯基)-2,2-二氯乙酮肟7f的X射线晶体学分析的基础上,对肟进行立体化学分配。1-芳基-2,2-二卤代乙酮肟与四氮化四硫反应,回流1,4-二恶烷,得到3-芳基-4-氯-1、3-芳基-4-溴-2和3-芳基-4 -氟-1,2,5-噻二唑3的产率分别为69-98、49-99和32-65%。提出了形成1,2,5-噻二唑的机理。
1-芳基-2,2-二卤代乙酮肟与四氮化四硫(S 4 N 4)的反应:合成3-芳基-4-卤代-1,2,5-噻二唑的一般方法
摘要:
1-芳基-2,2-二氯-7、1-芳基-2,2-二溴-8、1-芳基-2-溴-2-氟-9和1-芳基-2-氯-2-氟-通过在室温下在EtOH中使相应的酮与盐酸羟胺反应来制备乙酮肟10。在1 H NMR光谱证据和1-(3-氯苯基)-2,2-二氯乙酮肟7f的X射线晶体学分析的基础上,对肟进行立体化学分配。1-芳基-2,2-二卤代乙酮肟与四氮化四硫反应,回流1,4-二恶烷,得到3-芳基-4-氯-1、3-芳基-4-溴-2和3-芳基-4 -氟-1,2,5-噻二唑3的产率分别为69-98、49-99和32-65%。提出了形成1,2,5-噻二唑的机理。
α,α-Alkylation-Halogenation and Dihalogenation of Sulfoxonium Ylides. A Direct Preparation of Geminal Difunctionalized Ketones
作者:Rafael D. C. Gallo、Anees Ahmad、Gustavo Metzker、Antonio C. B. Burtoloso
DOI:10.1002/chem.201704609
日期:2017.12.1
A one‐pot alkylation–halogenation of ketosulfoxonium ylides in the presence of alkyl halides is described. The method furnishes several gem‐difunctionalized haloketones (an alkyl and F, Cl, Br, or I) in good yields. Replacing alkyl halides with a mixture of electrophilic halogen species and various halide anions led to gem‐dihalogenated ketones containing a combination of the same or two different
A nickel-catalyzed couplingreaction of α-bromo-α-fluoroketones with arylboronic acids was reported, which provides an efficient pathway to access 2-fluoro-1,2-diarylethanones in high yields. We also disclosed the synthesis of the monofluorination agents α-bromo-α-fluoroketones by using a trifluoroacetate release protocol. Mechanistic investigation indicated that a monofluoroalkyl radical is involved