共查询到20条相似文献,搜索用时 15 毫秒
1.
KBr acts as an efficient and reusable catalyst for the selective and efficient trimethylsilylation of benzylic, primary and secondary aliphatic alcohols and phenols with hexamethyldisilazane. All reactions were performed at room temperature under mild and completely heterogeneous conditions in good to high yields. 相似文献
2.
F. Shirini N. Ghaffari Khaligh 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2156-2165
Abstract Succinimide-N-sulfonic acid (SuSA) is easily prepared by the reaction of succinimide with chlorosulfonic acid. This reagent is able to efficiently catalyze the chemoselective trimethylsilylation of alcohols and phenols with hexamethyldisilazane (HMDS). All reactions were performed under mild reaction conditions, giving excellent yields. GRAPHICAL ABSTRACT 相似文献
3.
Hamid Reza Shaterian Fahimeh Khorami Azita Amirzadeh Majid Ghashang 《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2865-2874
A highly efficient and mild procedure for the trimethylsilylation of a wide variety of alcohols, including primary, benzylic, secondary, hindered secondary, tertiary, phenols, and oximes with hexamethyldisilazane (HMDS) using alumina perchloric acid (Al 2 O 3 -HClO 4 ) as recyclable heterogeneous catalyst in excellent yields with short reaction times (3?65 min) under ambient conditions is described. 相似文献
4.
《Phosphorus, sulfur, and silicon and the related elements》2013,188(11):2357-2361
A mild and efficient method for the synthesis of symmetrical ethers using silica sulfuric acid is reported. All reactions are performed under compeletly heterogeneous conditions in good to high yields. 相似文献
5.
Liqiang Wu Pengli Sun Fulin Yan 《Phosphorus, sulfur, and silicon and the related elements》2013,188(10):2055-2060
Abstract A highly convenient method for the trimethylsilylation of alcohols and phenols via treatment by hexamethyldisilazane in the presence of melamine trisulfonic acid as a catalyst has been developed. A wide variety of hydroxyl groups were selectively protected under solvent-free conditions. GRAPHICAL ABSTRACT 相似文献
6.
A simple, efficient, and rapid method for high-yielding regioselective mono bromination of phenols and anilines has been achieved by treatment with N-bromasaccharin in the presence of a catalytic amount of tungstophosphoric acid. 相似文献
7.
An easy method for the preparation of trimethylsilyl ethers from alcohols and 1,1,1,3,3,3‐hexamethyl‐disilazane (HMDS) using silica sulfate as a catalyst under mild conditions in excellent yields is described. 相似文献
8.
A straightforward and effective procedure for the conversion of benzylic and allylic alcohols to the corresponding iodides using KI/SSA in acetonitrile at room temperature. 相似文献
9.
In this report, substituted coumarins are formed via Pechmann condensation using various substituted phenols and ethyl acetoacetates in the presence of xanthan sulfuric acid as a solid acid catalyst under solvent-free conditions. This method is very simple, cost-effective, and has shorter reaction times, and the catalyst could be reused. 相似文献
10.
Ahmad Shaabani Ebrahim Soleimani Zahra Badri 《Monatshefte für Chemie / Chemical Monthly》2006,137(2):181-184
Summary. Silica sulfuric acid as an inexpensive and recyclable solid acid efficiently catalyzes the Fridedl?nder synthesis of quinolines through a condensation reaction of a 2-aminoaryl ketone with an activated α-CH acid compound under
solvent-free conditions in high yields at 100°C. 相似文献
11.
Lin Fei XIAO Jia Jian PENG Chun Gu XIA 《中国化学快报》2006,17(5):617-620
The conversion of ketoxime into corresponding amide, known as the Beckmann rearrangement, is a common method used in organic chemistry and is also a topic of current interest. It accomplishes both the cleavage of carbon-carbon bond and the formation of a carbon-nitrogen bond, and represents a powerful method particularly for manufacture ε-caprolactam in chemical industry. This reaction, however, generally requires high reaction temperature, strong Br?nsted acid and dehydrating media, causing … 相似文献
12.
Min Wang Zhi-Guo Song Heng Jiang Hong Gong 《Monatshefte für Chemie / Chemical Monthly》2007,138(6):599-602
Summary. Copper(II) chloride-acetic acid was found to be an efficient synergistic catalytic system for the tetraphydropyranylation
of various alcohols and phenols in high yields at room temperature in short reaction times. 相似文献
13.
B. Suresh Kuarm J. Venu Madhav S. Vijaya Laxmi Y. Thirupathi Reddy P. Narsimha Reddy 《合成通讯》2013,43(12):1719-1724
A series of 1-oxo-hexahydroxanthene derivatives was synthesized at room temperature in solid state from substituted salicylaldehydes and substituted 1,3-hexanediones in the presence of a catalytic amount of cellulose sulfuric acid. The results showed that the reaction performed under solid-state conditions was benign to the environment, with higher yields and more convenient workup.
14.
Mohammad Ali Zolfigol Gholamabbas Chehardoli Mina Dehghanian Khodabakhsh Niknam Farhad Shirini Ahmad Khoramabadi‐Zad 《中国化学会会志》2008,55(4):885-889
A mixture of ethyl formate and a catalytic amount of silica sulfuric acid or Al(HSO4)3 as suitable formylating systems can formylate various alcohols to their corresponding formate ester derivatives under mild, nearly neutral and heterogeneous conditions at room temperature with good to excellent yields. 相似文献
15.
BiBi Fatemeh Mirjalili Mohamad Ali Zolfigol Abdolhamid Bamoniri Amin Zarei 《Phosphorus, sulfur, and silicon and the related elements》2013,188(8):1845-1849
A combination of silica sulfuric acid and sodium dichromate dihydrate in the presence of wet SiO 2 were used as an effective oxidizing agent for the oxidation of alcohols to their corresponding aldehyde or ketone derivatives in dichloromethane or toluene with excellent yields. 相似文献
16.
B. Suresh Kuarm J. Venu Madhav Y. Thirupathi Reddy P. Narsimha Reddy Peter A. Crooks 《合成通讯》2013,43(5):662-669
An efficient method for the synthesis of 2-substituted benzimidazoles has been developed. In this method, benzo[c][1,2,5]thiadiazole-4,5-diamine was condensed with different aldehydes in the presence of cellulose sulfuric acid under solvent-free conditions by simple physical grinding of reactants using a mortar and pestle at room temperature. The methodology is mild, high-yielding, and green, and the catalyst could be easily recycled. 相似文献
17.
Jianzhong Jiang Li Dai Zhe Cui Liting Lu Zhenggang Cui 《Journal of Dispersion Science and Technology》2014,35(4):524-527
Highly regiospecific mononitration of phenol by NaNO3 and dilute sulfuric acid was carried out in a TX100 oil-in-water microemulsion. Effects of various parameters such as acid type, surfactant concentration, water content, and alcohol have been investigated. The use of inexpensive and relatively nontoxic acidic reagent is an advantage of this method. 相似文献
18.
Structurally diverse alcohols and phenols were efficiently transformed into their corresponding trimethylsilyl ethers with hexamethyldisilazane (HMDS) in the presence of catalytic amounts of sulfamic acid (SA) at room temperature under both acetonitrile and solvent-free conditions. Deprotection of these trimethylsilyl ethers to their parent alcohols and phenols was also achieved using this catalyst in water at room temperature. 相似文献
19.
Akbar Mobinikhaledi Naser Foroughifar Mohammad Ali Bodaghi Fard Hassan Moghanian Sattar Ebrahimi Mehdi Kalhor 《合成通讯》2013,43(7):1166-1174
An efficient Hantzsch four-component condensation reaction for the synthesis of polyhydroquinoline derivatives was reported under two conditions: solvent-free conventional heating and energy-saving microwave irradiation. The process is simple and environmentally benign, and the use of a heterogeneous and reusable catalyst, high yields, and short reaction times are the key features of this protocol. 相似文献
20.
Carbonyl compounds have been successfully converted into their corresponding dithiolane, dithiane, and oxathiolane derivatives using a catalytic amount of alumina sulfuric acid (Al2O3–SO3H) with excellent yields at room temperature in short reaction times under mild conditions. This simple method is a highly chemoselective procedure for protection of aldehydes in the presence of ketones, and the heterogeneous catalyst can be recovered and reused several times without any loss of its activity. 相似文献