排序方式: 共有68条查询结果,搜索用时 15 毫秒
41.
Xiu Wang 《Tetrahedron letters》2007,48(34):6010-6013
In the presence of 1-5 mol % of benzyltriphenylphosphonium chloride, a wide variety of unconjugated and conjugated, acyclic and cyclic ketones were transformed to their corresponding cyanohydrin silyl ethers in excellent yields. 相似文献
42.
Copper-catalyzed cyanation of aryl halides was improved to be more economical and environmentally friendly by using water as the solvent and ligand-free Cu(OAc)2·H2O as the catalyst under microwave heating. The suggested methodology was applicable to a wide range of substrates including aryl iodides and activated aryl bromides. 相似文献
43.
A practical and efficient oxidative CH cyanation of secondary benzylic ethers with TMSCN in the presence of DDQ is described for the first time. The metal-free process is well tolerated with a wide variety of electronically varied α-monosubstituted isochromans for the synthesis of isochromans bearing α-aryl α-cyano substituent patterns. 相似文献
44.
Liangzhen Hu Muhammad Ijaz Hussain Qingfu Deng Qing Liu Yangyang Feng Xiaohui Zhang Yan Xiong 《Tetrahedron》2019,75(2):308-314
One-step base promoted strategy for cyanation of α,α-diaryl alcohols has been developed under mild and transition metal-free conditions. This method provides a straightforward and facile way towards the synthesis of β,γ-unsaturated nitriles and α-phenylnitiriles from α-vinyl carbinols and α,α-diaryl methanols, respectively, up to 99% yield. Moreover, various azides and ethers could also be accessed from their respective nucleophiles under standard reaction conditions. 相似文献
45.
Alexandra Budanow Klaus‐Dieter Franz Hannes Vitze Lothar Fink Edith Alig Michael Bolte Matthias Wagner Hans‐Wolfram Lerner 《无机化学与普通化学杂志》2017,643(3):243-249
A series of adducts of LiCN, namely [Li(Me2CO3)CN], [Li(Et2CO3)CN], and [Li(NMP)CN] (NMP = N‐methyl‐2‐pyrrolidone) were prepared by treatment of solvent‐free LiCN with the appropriate donor. The starting material for these approaches, donor‐free LiCN, was quantitatively prepared from Me3SiCN and Li[Me] in diethyl ether at 0 °C. Alternatively, [Li(NMP)CN] was synthesized by metathesis reaction of LiCl with NaCN in the presence of stoichiometric amounts of NMP. Although [Li(Me2CO3)CN] and [Li(Et2CO3)CN] are water‐sensitive compounds and decompose at the exposure to air, [Li(NMP)CN] is stable in air, even at elevated temperatures. The thermal stability of [Li(NMP)CN] was proven by differential thermal analysis (DTA). [Li(NMP)CN] shows thermal stability up to temperatures of about 132 °C. To evaluate the cyanation ability the reactions of 1‐bromooctane and 3‐bromocyclohexene with unsupported LiCN, [Li(NMP)CN], and a mixture of NaCN/LiCl/NMP were investigated. We found that [Li(NMP)CN] as well as LiCl/NaCN/NMP are efficient cyanation reagents comparable to the expensive and air‐sensitive, donor‐free LiCN. A product of the chloride‐cyanide‐bromide exchange could be isolated and structurally characterized by X‐ray diffraction. 相似文献
46.
Yunlai RenMengjie Yan Shuang ZhaoYanpei Sun Jianji Wang Weiping YinZhifei Liu 《Tetrahedron letters》2011,52(39):5107-5109
Non-toxic K4[Fe(CN)6] was demonstrated to be effective as a green cyanating agent for the cyanation of alkyl halides using PPh3/Pd(OAc)2 as a catalyst system. The presented method allowed a series of benzyl chlorides to be smoothly cyanated in up to 88% yield. In order to avoid or suppress the deactivation of the catalyst, the reaction was required to be performed in a stringent inert ambiance. 相似文献
47.
Manirul Islam Paramita Mondal Anupam Singha Roy Dilder Hossain 《Journal of organometallic chemistry》2010,695(21):2284-529
An inexpensive, air-moisture stable and reusable PS-Pd(II)-anthra complex was synthesized by reacting chloro-methylated polystyrene with anthranilic acid to get polymer anchored ligand which was then reacted with PdCl2 to get polymer anchored complex. This complex was characterized by different spectroscopic and elemental analyses. The activity of the Pd-complex as catalyst was tested for the Suzuki, Heck, Sonogashira cross-coupling and also for amination and cyanation reactions under various conditions. The catalyst exhibits high catalytic activities for the coupling of various aryl halides with organoboronic acid, alkene, alkyne and amine along with the cyanation of aryl halides providing excellent yields of desired product. Further, the catalyst can be easily recovered quantitatively by simple filtration and reused up to five times without sufficient loss of its catalytic activity. 相似文献
48.
Copper-catalyzed direct cyanation of terminal alkynes is achieved using less toxic, stable and easy to handle benzoyl cyanide as a cyanide source and air as an oxidant. This protocol provides a good alternative to the preparation of 3-arylpropiolonitriles under mild condition. 相似文献
49.
Xiaohui Fan Kun Guo Yong-Hong Guan Lin-An Fu Xiao-Meng Cui Hao Lv Hong-Bo Zhu 《Tetrahedron letters》2014
A novel and practical method for the synthesis of diverse α-aryl and α-vinyl nitriles was developed via an iron-catalyzed sp3 C–O ether bond cleavage with C–C bond formation in the reaction of π-activated ethers with TMSCN. 相似文献
50.