Unexpected regio- and chemoselectivity of cationic gold-catalyzed cycloisomerizations of propargylureas: access to tetrasubstituted 3,4-dihydropyrimidin-2(1H)-ones.
نویسندگان
چکیده
Cationic gold-catalyzed cycloisomerizations of propargylureas, derived in situ from secondary propargylamines and aryl or alkyl isocyanates, have been studied. The reaction outcome was found to be different from what was previously observed for the tosyl isocyanate-derived ureas in terms of both regio- and chemoselectivity. As a result, the current protocol offers efficient access to the 3,4-dihydropyrimidin-2(1H)-one core through the 6-endo-dig N-cyclization.
منابع مشابه
Solvent-free Biginelli Reaction Catalyzed to Synthesis of Biologically Active 3,4-dihydropyrimidin-2-(1H) –ones/thiones Derivatives
A convenient and highly efficient procedure for the synthesis of 3,4-dihydropyrimidin-2-(1H)-one/thione derivatives via one-pot three-component Biginelli condensation of arylaldehydes,urea/thiourea and ethyl/methyl acetoacetate in the presence of Zn(SO4)2.7H2Oas anefficient, readily and inexpensive catalyst under solvent-free conditions have been studied. Thisprotocol ha...
متن کاملSolvent-free and one-pot Biginelli synthesis of 3,4-dihydropyrimidin-2(1H)-ones and 3,4-dihydropyrimidin-2(1H)-thiones using ionic liquid N,N-diethyl-N-sulfoethanammonium chloride {[Et3N–SO3H]Cl} as a green catalyst.
In this work, the ionic liquid triethylamine-bonded sulfonic acid {[Et3N–SO3H]Cl}, N,N-diethyl-N-sulfoethanammonium chloride was used as a green acidic homogeneous catalyst to synthesis of 3,4-dihydropyrimidin-2(1H)-ones and 3,4-dihydropyrimidin-2(1H)-thiones as two categories of heterocycles, from aldehyde, dicarbonyl compound and urea or thiourea throughout the one-pot three components cycloc...
متن کاملSbCl5.SiO2: an reusable lewis acid for one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones (thiones)
Nano-SbCl5.SiO2 and SbCl5.SiO2 are bench-top catalysts which are reusable, readily available, versatile andefficient for promotion of many acid catalyzed organic reactions. These catalysts do not need specialprecautions for preparation, handling or storage, and they can be stored at an ambient temperature for monthswithout losing their catalytic activity. 4-dihydropyrimidin-2(1H)-ones(thiones) ...
متن کاملHighly efficient multicomponent Biginelli’s synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by Al-MCM-41 under solvent-free conditions
In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
متن کاملHighly efficient multicomponent Biginelli’s synthesis of 3,4-dihydropyrimidin-2(1H)-ones catalyzed by Al-MCM-41 under solvent-free conditions
In this study, an efficient and green process for the synthesis of dihydropyrimidin-2(1H)-ones from aromatic benzaldehydes, ethyl acetoacetate and urea using Al-MCM-41 as heterogeneous catalyst and microreactor under solvent-free conditions has been developed. The advantages of this method are easy work-up procedure, regeneration of the catalyst, clean and neutral reaction conditions.
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 12 11 شماره
صفحات -
تاریخ انتشار 2014