Direct chlorination of alcohols with chlorodimethylsilane catalyzed by a gallium trichloride/tartrate system under neutral conditions.
نویسندگان
چکیده
The reaction of secondary alcohols 1 with chlorodimethylsilane (HSiMe(2)Cl) proceeded in the presence of a catalytic amount of GaCl(3)/diethyl tartrate to give the corresponding organic chlorides 3. In the catalytic cycle, the reaction of diethyl tartrate 4a with HSiMe(2)Cl 2 gives the chlorosilyl ether 5 with generation of H(2). Alcohol-exchange between the formed chlorosilyl ether 5 and the substrate alcohol 1 affords alkoxychlorosilane 6, which reacts with catalytic GaCl(3) to give the chlorinated product 3. The moderate Lewis acidity of GaCl(3) facilitates chlorination. Strong Lewis acids did not give product due to excessive affinity for the oxy-functionalities. Although tertiary alcohols were chlorinated by this system even in the absence of diethyl tartrate, certain alcohols that are less likely to give carbocationic species were effectively chlorinated using the GaCl(3)/diethyl tartrate system.
منابع مشابه
Silylation of Alcohols and Phenols Using HMDS Catalyzed by SiO2-Cl in Solution and Solvent-Free Conditions
Trimethylsilylation of a variety of alcohols and phenols, in the presence of silica chloride, using hexamethyldisilazane (HMDS) in solution and under solvent-free conditions is reported. Trimethylsilyl ethers were formed in excellent yields both for aliphatic alcohols and phenols without having an electron-withdrawing group. In addition, SiO2-Cl can be recovered and reused after drying.
متن کاملCyanation and bromination of electron-rich aromatics by BrCN under solvent-free conditions catalyzed by AlCl3: A new examples of Beckmann-type rearrangement
A convenient route for cyanation and bromination of some electron-rich aromatics (anisole, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,3,5-trimethoxybenzene and β-naphthol) by BrCN in the presence of aluminum trichloride (AlCl3), as catalyst, by grinding method under solvent-free conditions at room temperature to 60 °C was described in good yield. The structures of all obtained products were ...
متن کاملDirect coupling of alcohols with alkenylsilanes catalyzed by indium trichloride or bismuth tribromide.
Indium halides or bismuth halides catalyzed the coupling of various alcohols with alkenylsilanes to give the corresponding alkenes stereospecifically without any other activators.
متن کاملSelective trimethylsilylation of alcohols and phenols with hexamethyldisilazane catalyzed by LaCoO3 perovskite
Trimethylsilylation of alcohols and phenols were carried out under solvent-free conditions with hexamethyldisilazane (HMDS) using LaCoO3 perovskite. LaCoO3 as an efficient catalyst accelerated this reaction under milder condition. The advantages of this method are evident regarding, easy separation, low cost and low catalyst loading, lack of pollution, easy work-up, and selective protection of ...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Organic & biomolecular chemistry
دوره 6 15 شماره
صفحات -
تاریخ انتشار 2008