Default Latest Most Read Please wait a minute... Chlorosulfonation of Acetanilide in a Dual-Temperature-Zone Silicon Carbide Microchannel Reactor and Synthesis of Sulfasalazine Zhang Zishu, Zhao Yulong, Geng Huiling Chinese Journal of Organic Chemistry 2020, 40 (8): 2387-2393. DOI: 10.6023/cjoc202003053 Published: 10 June 2020 Abstract (1460) PDF (1017KB)(1369) Knowledge map Chlorosulfonation of acetanilide was accomplished within 10 min in up to 96% yield via a highly thermoconductive and corrosion-resistant dual-temperature-zone silicon carbide microchannel reactor. The yield of pilot production was up to 92%. In the first stage, low reaction temperature (40℃) was employed to effect a high sulfonation selectivity at the para position of acetanilide. In the second stage, a higher reaction temperature (100℃) led to a faster formation of chlorosulfonation product. To illustrate the application of this reaction, sulfasalazine with antimicrobial and anti-inflammatory activities was synthesized in total yield of 75% via chlorosulfonation, sulfamide formation, hydrolysis under base conditions, diazotization and coupling with salicylic acid. The two-step continuous reaction helped to solve the problems in batch reactor, such as low temperature leading to slow reaction and high temperature resulting byproducts and/or temperature runaway, the safety concern aroused by heat accumulation, and the polution caused by the use of large excess of chlorosulfonic acid in batch production. The above research provides technical support for the large-scale industrial production of p-acetylaminobenzenesulfonyl chloride and its sulfonamides. Reference | Supporting Info. | Related Articles | Metrics Articles Cobalt-Catalyzed Dehydrogenative Silylation of Vinylarenes Cheng Biao, Lu Peng, Zhao Jiajin, Lu Zhan Chin. J. Org. Chem. 2019, 39 (6): 1704-1710. DOI: 10.6023/cjoc201903018 Published: 16 April 2019 Abstract (1310) PDF (1197KB)(1081) Knowledge map A highly chemo-, regio-, and stereo-selective cobalt-catalyzed dehydrogenative silylation of vinylarenes was described. The imidazoline iminopyridine cobalt complex could promote this reaction effectively and improve the chemoselectivity dramatically. This protocol used earth-abundant transition metal, readily available alkenes and hydrosilanes to construct valuable vinylsilanes. The reaction could be carried out in gramscale and the proposed mechanism was also described. Reference | Supporting Info. | Related Articles | Metrics Reviews Recent Advance in Transition-Metal-Catalyzed Silylation of C-H Bonds Huang Hongtai, Li Tao, Wang Jiazhuang, Qin Guiping, Xiao Tiebo Chin. J. Org. Chem. 2019, 39 (6): 1511-1521. DOI: 10.6023/cjoc201903078 Published: 28 May 2019 Abstract (1251) PDF (1536KB)(1853) Knowledge map Organosilicon compounds play an important role in pharmaceutical chemistry, material science and organic synthesis. Transition-metal-catalyzed direct silylation of C-H bond, as one of the most concise and efficient methods for the synthesis of organosilanes, has developed rapidly in recent years. In this paper, the recent advance in transition-metal-catalyzed silylation of C-H bonds since 2015 is mainly reviewed. Reference | Related Articles | Metrics Cross-Coupling of C-Si Bond by Using Silyl Reagents Wang Mingfeng, Yu Maodong, Wang Wenshu, Lin Weili, Luo Feixian Chinese Journal of Organic Chemistry 2019, 39 (11): 3145-3153. DOI: 10.6023/cjoc201904024 Published: 24 June 2019 Abstract (1239) HTML (49) PDF (596KB)(2138) Knowledge map Organosilanes have been widely applied in synthetic chemistry, pharmaceuticals, agrochemicals, and materials due to the special properties. Several synthetic strategies including nucleophilic substitution, hydrosilylation of alkene, and C-H silylation have been developed. In recent years, significant progress has advanced in the cross-coupling of C-Si bond for the synthesis of organosilanes, especially in the break-through of the cross-coupling of C(sp3)-Si bond. It has become one of the hottest issues in synthetic chemistry. The recent progress on the cross-coupling of C-Si bond by using silyl reagents is summarized. The application of silyl reagents in cross-coupling for C-Si bond formation including silyl boranes, organosilyl magnesium, organosilyl zinc, unasymetric disilanes, organosilyl aluminum and organosilyl lithium reagents is mainly discussed. Fig. & Tab. | Reference | Related Articles | Metrics Palladium-Catalyzed Reductive Coupling of Aromatic Bromides and Trimethylsilyldiazomethane: Its Application to Methylation of Aromatic Compounds Wang Shuai, Yang Cheng, Sun Shuo, Sun Hanli, Wang Jianbo Chinese Journal of Organic Chemistry 2020, 40 (11): 3881-3888. DOI: 10.6023/cjoc202006075 Published: 06 August 2020 Abstract (1099) PDF (560KB)(949) Knowledge map The introduction of methyl group into aromatic compounds is a valuable transformation. A large number of known methods use organohalides as the starting materials. However, those methods require pre-synthesized methyl metal reagents or toxic methyl electrophiles. Herein, a palladium-catalyzed reductive coupling reaction between aryl bromides and trimethylsilyl-diazomethane is developed, and the following desilicification process can afford the methylated products. This transformation has broad functional group tolerance and allows methylation of (hetero)aryl halides in moderate to good yields. Thus, it has the potential to be an attractive approach for methylation of organic. In addition, this reductive coupling can also serve as an efficient way for the introduction of silylmethyl group. Reference | Supporting Info. | Related Articles | Metrics Progress in Catalysis of Hydrosilylation by Cobalt Complexes Dai Zinan, Yu Zehao, Bai Ying, Li Jiayun, Peng Jiajian Chinese Journal of Organic Chemistry 2020, 40 (5): 1177-1187. DOI: 10.6023/cjoc201910012 Published: 03 January 2020 Abstract (1088) PDF (734KB)(1543) Knowledge map Cobalt is abound in the earth and has advantages of low cost and low toxicity. Cobalt complexes have been widely applied as catalysts in numerous catalytic organic reactions, in which the complexes show excellent catalytic performance and have been recognized as a very important research field. The recent progress in the application of cobalt complexes in the catalytic hydrosilylation of alkenes, alkynes, carbonyl compounds and other unsaturated double bond is summarized. Furthermore, the deficiencies of the catalysts have been discussed. At last, the future development and prospects of these complexes as catalysts are also proposed. Reference | Related Articles | Metrics Synthesis of β,β-Dichloro-α,β-unsaturated Ketones by Trichloro-methyl Radical Addition/Elimination of Enol Silyl Ethers Ge Haochen, Du Keying, Sheng Weijian Chinese Journal of Organic Chemistry 2020, 40 (6): 1625-1629. DOI: 10.6023/cjoc201911023 Published: 31 March 2020 Abstract (989) PDF (498KB)(977) Knowledge map Using di-tert-butyl peroxide (DTBP) as oxidant, chloroform or carbon tetrachloride as trichloromethyl radical source and reaction solvent, enol silyl ethers derived from aryl ketone was transferred to β,β-dichloro-α,β-unsaturated ketone by trichloromethyl radical addition/elimination. The conditions are mild with avoiding the use of metal catalysts, and the enol silyl ethers substrate has good universality. Reference | Supporting Info. | Related Articles | Metrics Chiral Spiro Dienes Derived Boranes for Asymmetric Hydrosilylation of Ketones Wang Qiaotian, Han Caifang, Feng Xiangqing, Du Haifeng Chin. J. Org. Chem. 2019, 39 (8): 2257-2263. DOI: 10.6023/cjoc201903076 Published: 10 May 2019 Abstract (945) PDF (552KB)(1158) Knowledge map The chemistry of frustrated Lewis pairs (FLPs) is among the challenging frontiers of synthetic chemistry, which provides a powerful approach for metal-free catalytic hyrogenations and Piers-type hydrosilylations. In recent years, a significant progress has been made in this field. However, the deveopment of asymmetric reactions is still sluggish. The lacks of highly effective and enantioselective chiral FLP catalysts represent the key issue. C2-symmetric 1,1'-spirobiindane is one privileged framework in chiral ligands and catalysts. On the basis of chiral binaphthyl diene-derived frustrated Lewis pairs (FLPs) developed by our group, in this work, we designed and synthesized a novel class of chiral spiro dienes, which could further react with Piers' borane via the hydroboration reaction to generate chiral boranes in situ. With the combination of chiral borane and tri-tert-butylphosphine as an FLP catalyst, an asymmetric Piers-type hydrosilylation of simple ketones was successfully realized to give the desired secondary alcohols with up to 90% ee. Reference | Supporting Info. | Related Articles | Metrics Notes Preparation of Hydrophobic SiO2 Aerogel by Rapid Solvents Exchange Method and Its Application Loaded with Organic Fluorescence Probe Wang Yafei, Zhang Tao, Guo Xudong, Hu Rui, Wang Shuangqing, Yang Guoqiang Chin. J. Org. Chem. 2019, 39 (2): 550-554. DOI: 10.6023/cjoc201808002 Published: 26 September 2018 Abstract (883) PDF (1374KB)(1209) Knowledge map Aerogel is a kind of gel materials, of which the fluid phase is gas. Aerogel has the characteristics of low density and high porosity, and has a wide application prospects. In this work, a rapid solvents exchange method was developed, and using in-situ secondary extraction, rapid solvents exchange in aerogel preparation was achieved through the miscibility and immiscibility of ethanol-dichloromethane-water. Combined with hydrophobic treatment and vacuum drying, hydrophobic silica aerogel was obtained. The aerogel had a low density and a contact angle with water of 155.8°. The aerogel can load various organic fluorescent probe dyes, which can effectively avoid the fluorescence quenching caused by the aggregation of the probe molecules, which it will expand the practical application range of the organic fluorescent probes in wider fields. Reference | Supporting Info. | Related Articles | Metrics NOTES Direct Nucleophilic Substitution of Propargyl Alcohols with Enoxysilanes Xinling Li, Huili Liu, Shunji Zhang Chinese Journal of Organic Chemistry 2021, 41 (1): 407-411. DOI: 10.6023/cjoc202007011 Published: 27 August 2020 Abstract (854) HTML (16) PDF (390KB)(527) Knowledge map A novel and efficient synthesis of γ-alkynyl ketones by the direct nucleophilic substitution of propargyl alcohols with enoxysilanes in the presence of a catalytic amount of p-toluenesulfonic acid monohydrate, has been developed. The reactions can be performed in an undried solvent under an air atmosphere to obtain the desired products in good yields. Fig. & Tab. | Reference | Supporting Info. | Related Articles | Metrics Tris(trimethylsilyl)silane/O2-Promoted and Photo-accelerated Conversion of Alkyl Iodides to Alcohols Li Jianyu, Zeng Jinlong, Chen Jianfeng, Zhao Baoguo Chinese Journal of Organic Chemistry 2020, 40 (11): 3853-3857. DOI: 10.6023/cjoc202006055 Published: 19 August 2020 Abstract (840) PDF (490KB)(670) Knowledge map A mild method for the conversion of alkyl iodides to alcohols was developed. The transformation was promoted by tris(trimethylsilyl)silane/O2 and accelerated by photoredox catalysis under visible light irradiation conditions. Various alkyl iodides, including primary, secondary and tertiary iodides, can be smoothly converted to the corresponding alcohols in 38%~99% yields. Reference | Supporting Info. | Related Articles | Metrics Study on Allylation Reactions of Trifluoromethylated Acylhydrazones with Allylsilanes or Allylboronates Hu Yongqin, Huang Danfeng, Wang Kehu, Zhao Zhuanxia, Zhao Fangxia, Xu Weigang, Hu Yulai Chinese Journal of Organic Chemistry 2020, 40 (6): 1689-1696. DOI: 10.6023/cjoc201912006 Published: 04 March 2020 Abstract (795) PDF (521KB)(776) Knowledge map Allylation reactions of trifluoromethylated acylhydrazones with allyltrimethylsilane or pinacolyl allylboronate were found to proceed smoothly in the presence of Lewis acid to afford a series of trifluoromethylated homoallylic N-acylhydrazines with high yields. The results showed that the activity of pinacolyl allylboronate was higher than that of allyltrimethylsilane in allylation of trifluoromethylated acylhydrazones. Reference | Supporting Info. | Related Articles | Metrics Studies on the Stereoselective Synthesis of Functionalized Allylsilane Compounds Jiang Quan, He Ling, Li Weidong Chinese Journal of Organic Chemistry 2019, 39 (12): 3454-3459. DOI: 10.6023/cjoc201904081 Published: 30 August 2019 Abstract (713) PDF (492KB)(915) Knowledge map Allylsilanes have emerged as synthetically useful intermediates that can undergo a variety of chemical transformations and have been found versatile applications in C-C bond construction as well as in preparation of complex molecules. Exploration on the stereoselective route to functionalized allylsilanes is of great significance for the development of organic synthetic methodology. An efficient pathway to a series of novel alkoxy-substituted homoiodio-allylsilanes via the Julia olefination of silylmethyl cyclopropyl carbinols was described. Carbinols derived from cyclopropyl aryl ketone were evidenced to be superiorer in controlling the stereoselectivity of the products than the alkyl equivalents. Reference | Supporting Info. | Related Articles | Metrics Notes Synthesis of Azoxybenzenes by Selective Oxidation of Anilines on Titanium Silicate Molecular Sieves Song Yuwan, Feng Shaojing, Han Wei, Xiao Yaping Chin. J. Org. Chem. 2019, 39 (4): 1181-1186. DOI: 10.6023/cjoc201808032 Published: 30 November 2018 Abstract (704) PDF (633KB)(627) Knowledge map A convenient method for improving the conversion and selectivity of aniline to azoxybenzene by adjusting the ratio of silicon to titanium of TS-1 is reported. Over TS-1 (80), aryl anilines are transformed into the corresponding azoxybenzenes in good yields with H2O2 as the oxidant. The effect of different reaction parameters like molar ratio of H2O2 to aniline, solvent and the activity in catalyst recycling has been studied. Reference | Supporting Info. | Related Articles | Metrics Articles Potassium Phenyltrifluoroborate-Catalyzed Reduction of Aldehydes and Ketones into Alcohol with Silanes Liu Jianhui, Wang Xingyang Chin. J. Org. Chem. 2019, 39 (5): 1411-1416. DOI: 10.6023/cjoc201810010 Published: 18 January 2019 Abstract (648) PDF (437KB)(789) Knowledge map The selective reduction of carbonyl group with organosilane as reducing agent was studied with methanol as a solvent under the action of 2.5 mol% C6H5BF3K and 2.2 epuiv. (EtO)3SiH. The target products were obtained in medium to high yield. This method shows good selectivity and provides a new method for carbonyl reduction. Reference | Supporting Info. | Related Articles | Metrics Base-Promoted Rapid Hydrosilylation of Aldimine Wang Zichao, Xu Youjun, Shi Shiliang Chinese Journal of Organic Chemistry 2020, 40 (10): 3463-3466. DOI: 10.6023/cjoc202005085 Published: 23 July 2020 Abstract (623) PDF (450KB)(773) Knowledge map Amines are important intermediates in organic synthesis. The hydrosilylation of imines provides a convenient method for the synthesis of amines. Transition metal and main group catalysts have been widely applied in the hydrosilylation of imines. However, it would be more practical to use simpler reaction conditions to realize such reactions. In this paper, a fast hydrosilylation of aldimine was realized by using cheap t-BuOK as the promoter, providing an efficient method for the synthesis of amines in high yield. This reaction features rapid reaction, facile conditions, and robust practicability. Reference | Supporting Info. | Related Articles | Metrics C-H Bond Functionalization of Si-Bound Methyl Group through a 1,5-Palladium Migration Process Song Zhenlei Chinese Journal of Organic Chemistry 2020, 40 (7): 2176-2179. DOI: 10.6023/cjoc202000043 Abstract (617) PDF (484KB)(656) Knowledge map Reference | Related Articles | Metrics Efficient Synthesis of β-Keto-α-hydroxy Secondary (Primary) Amides by Selective Aminocarbonylation of Vicinal Diketones Using Carbamoylsilane as an Amide Source Zhang Pengpeng, Han Shenghua, Chen Jianxin Chinese Journal of Organic Chemistry 2020, 40 (6): 1737-1744. DOI: 10.6023/cjoc202001020 Published: 31 March 2020 Abstract (592) PDF (509KB)(695) Knowledge map The selective aminocarbonylation of vicinal diketones using carbamoylsilane as an amide source affords β-keto-α-siloxyamide derivatives in 62%~90% yields under mild conditions without using any oxidants and catalysts. The steric hindrance, which is both from the groups of vicinal diketones and the carbamoylsilanes, affects reaction selectivity on two carbonyl groups. The methoxymethyl or benzyl used as an amino protecting group, can be easily converted into hydrogen atom leading to β-keto-α-hydroxy secondary or primary amides. The simple procedure allows the preparation of various β-keto-α-hydroxy amide derivatives including primary, secondary and tertiary β-keto-α-hydroxy amide derivatives. The reaction has the advantages of mild conditions, less by-products, high selectivity, good yield and simple post-treatment, and it is a new method for the efficient preparation of β-keto-α-hydroxyamides. Reference | Supporting Info. | Related Articles | Metrics Articles Synthesis of α-(N-Sulfonyl)amino Amides Derivatives Using Carbamoylsilanes as an Amide Source Han Yuling, Tong Wenting, Liu Hui, Chen Jianxin Chin. J. Org. Chem. 2018, 38 (8): 1993-2001. DOI: 10.6023/cjoc201803054 Published: 24 May 2018 Abstract (570) PDF (510KB)(624) Knowledge map α-(N-Sulfonyl)amino amide derivatives are directly synthesized in 71%~89% yields by the reaction of carbamoylsilanes with various N-sulfonylimines in benzene under catalyst-free conditions. The procedure can prepare both tertiary and secondary α-amino amides. A comparison of the results obtained from the N-sulfonylimines containing the variety of alkyl, aryl and heterocyclic ring indicated that the electronic effect was an important factor in the addition reaction, which influenced on the rate and yields of the reaction. The new method is simple and mild procedure, no catalysts conditions, less byproducts and good yields for the preparation of α-aminoamides. Reference | Supporting Info. | Related Articles | Metrics Palladium-Catalyzed[4+2] Annulation of Cyclopropenes with Benzosilacyclobutanes Wang Xichao, Zhao Dongbing Chinese Journal of Organic Chemistry 2020, 40 (4): 1080-1081. DOI: 10.6023/cjoc202000019 Abstract (555) PDF (406KB)(840) Knowledge map Reference | Related Articles | Metrics Notes Gold(I)-Catalyzed 1, 2-Migration of a SiMe3 Group on Naphthalene Rings Yang Qi, Liu Liang, Zhang Wen-Xiong, Xi Zhenfeng Chin. J. Org. Chem. 2018, 38 (1): 272-276. DOI: 10.6023/cjoc201708059 Published: 19 September 2017 Abstract (544) PDF (586KB)(1301) Knowledge map A gold(I)-catalyzed 1,2-silyl migration on 1,8-di-substituted naphthalene rings was realized by synergistic effect of Lewis acid and water. High yields were achieved under relatively mild conditions. Reference | Related Articles | Metrics Article Synthesis of Benzofuran Derivatives by Diphenylperhydroindolinol Silyl Ether-Catalyzed Asymmetric [3+3] Aza-cyclization ofα,β-Unsaturated Aldehydes Huiling Wen, Nianhua Luo, Lu Ouyang, Renshi Luo Chinese Journal of Organic Chemistry 2021, 41 (1): 348-356. DOI: 10.6023/cjoc202006036 Published: 27 August 2020 Abstract (524) HTML (10) PDF (511KB)(605) Knowledge map A highly enantioselective [3+3] aza-cyclization of α, β-unsaturated aldehydes with 3-aminobenzofuran promoted by diphenylperhydroindolinol silyl ether has been described, which afforded benzofuran derivatives in high yields (up to 93%), diastereoselectivities ( dr>20∶1) and enantioselectivities (86%~>99% ee). This method also enabled to obtain benzofuran derivatives in gram scale-up. Fig. & Tab. | Reference | Supporting Info. | Related Articles | Metrics Synthesis of 3-Hydroxy-3-heterocyclebutylamide Derivatives Using Carbamoylsilanes as an Amide Source Zhang Pengpeng, Chen Wenwen, Feng Hua, Chen Jianxin Chinese Journal of Organic Chemistry 2019, 39 (12): 3560-3566. DOI: 10.6023/cjoc201906033 Published: 07 August 2019 Abstract (498) PDF (609KB)(646) Knowledge map 3-Hydroxy-3-heterocyclebutyl amide derivatives were directly synthesized in 56%~85% yields by nucleophilic addition of various carbamoylsilanes to oxetane-3-one or thietane-3-one in toluene under mild and catalyst-free conditions. This method will provide an efficient route for the synthesis of drugs containing four-membered heterocycles which have not additional stereocentres. The procedure can prepare 3-hydroxy-3-heterocyclebutyl tertiary, secondary and primary amides as well as having a stereocentre connecting with nitrogen atom by selecting different carbamoylsilanes. A comparison of the results obtained from reaction of various carbamoylsilanes indicated that the size of group on the amide group was an important factor in the addition reaction, which influenced on both the reaction time and yields. The reaction has the advantages of mild conditions, less by-products, good yield and simple post-treatment, and is a new method for the efficient preparation of 3-hydroxy-3-heterocycle butylamides. Reference | Supporting Info. | Related Articles | Metrics