Catalytic Enantioselective Synthesis of Chiral Phthalides by SmI<sub>2</sub>-Mediated Reductive Cyclization of 2-Acylarylcarboxylates
作者:Ling-Lin Huang、Ming-Hua Xu、Guo-Qiang Lin
DOI:10.1021/ja061114z
日期:2006.5.1
A significant new and efficient catalytic asymmetric approach for the highly enantioselectivesynthesis of chiralphthalides by SmI2-induced reductivecyclization of 2-acylarylcarbonylates was developed. The combination of (4S,5R)-4,5-diphenyloxazolidin-2-one and 2,2,6,6-tetramethylpiperidine was found to be a very effective catalyst system in the reaction. This method provides a ready access to a
zed carbonylations involved either toxic carbon monoxide (CO) gas as carbonylating agent or functional-group-assisted ortho sp2 C–H activation (i.e., ortho acylation) or carbonylation by activation of the carbonyl group (i.e., via the formation of enamines). Contradicting these methods, here we describe an environmentally benign process, [Pd]-catalyzed direct carbonylation starting from simple and
Regioselective one pot synthesis of 1,2,3-triazole derivatives bearing phthalazine moiety and their pharmacological activity
作者:P. C. Shyma、Balakrishna Kalluraya、S. K. Peethambar、A. M. Vijesh
DOI:10.1007/s00044-016-1629-4
日期:2016.11
series of phthalazine-based 1,2,3-triazole derivatives (5a–h, 6a–f and 7a–d) were synthesized from the corresponding 2-(4-methyl/chloro benzyloxy) benzoic acid by multi-step reactions. Synthesized compounds were characterized by spectral studies and C, H, N analysis. The final compounds were screened for their antimicrobial, antifungal and antioxidant activity. Among them compounds 5c, 5g, 5h, 6b and
Catalyst for polymerization of olefin and process for the preparation of olefin polymer
申请人:SHOWA DENKO KABUSHIKI KAISHA
公开号:EP0640624A1
公开(公告)日:1995-03-01
A catalyst for producing a polyolefin having a high melting point and a high stereoregularity, which comprises: (A) a solid catalyst component containing titanium, magnesium and halogen, (B) an organic aluminum compound, and (C) an organic silicon compound represented by formula (1):
wherein R¹, R² and R³ each represents a C₁₋₃ hydrocarbon group.
Catalyst for olefin polymerization and process for producing polyolefin using the same
申请人:JAPAN POLYOLEFINS CO., LTD.
公开号:EP0717053A2
公开(公告)日:1996-06-19
A catalyst for olefin polymerization comprising: (A) a solid catalyst component comprising a titanium compound, a magnesium compound, and a halogen compound; (B) an organoaluminum compound; (C) a first organosilicon compound represented by formula (I):
wherein R¹ represents a hydrocarbon group having 1 to 4 carbon atoms; R² represents a hydrocarbon group having 1 to 6 carbon atoms or a hydrogen atom; R³ and R⁴ each represent a hydrocarbon group having 1 to 6 carbon atoms; and R², R³, and R⁴ may be the same or different; and (D) a second organosilicon compound represented by formula (II):
wherein R⁵ represents a hydrocarbon group having 1 to 4 carbon atoms; and R⁶, R⁷, and R⁸, which may be the same or different, each represent a hydrocarbon group having 1 to 6 carbon atoms or a hydrogen atom.