120390-74-1Relevant articles and documents
Chiral Covalent Organic Frameworks with High Chemical Stability for Heterogeneous Asymmetric Catalysis
Han, Xing,Xia, Qingchun,Huang, Jinjing,Liu, Yan,Tan, Chunxia,Cui, Yong
, p. 8693 - 8697 (2017)
Covalent organic frameworks (COFs) featuring chirality, stability, and function are of both fundamental and practical interest, but are yet challenging to achieve. Here we reported the metal-directed synthesis of two chiral COFs (CCOFs) by imine-condensat
Enantioselective silylcyanation of aldehydes and ketones by a titanium catalyst prepared from a partially hydrolyzed titanium alkoxide and a Schiff base ligand
Yoshinaga, Kazuhiko,Nagata, Takushi
, p. 1495 - 1498 (2009)
In the presence of small amount (0.2-1.0 mol%) of a titanium complex catalyst prepared from a partially hydrolyzed titanium alkoxide and an optically active tridentate Schiff base ligand, the enantioselective silylcyanation of aldehydes and ketones procee
Enantioselective Trimethylsilylcyanation of some Aldehydes Promoted by Modified Sharpless Catalyst
Hayashi, Masahiko,Matsuda, Tohru,Oguni, Nobuki
, p. 1364 - 1365 (1990)
A highly enantioselective method for trimethylsilylcyanation of a variety of aldehydes was developed using a modified Sharpless reagent.
Stereofacial control in asymmetric cyanosilylation of aldehydes catalyzed by novel S-proline-derived titanium complexes
Kim, Yun Bong,Kim, Min Kyoun,Kang, Sung Ho,Kim, Yong Hae
, p. 1995 - 1998 (2005)
Asymmetric cyanosilylation of aryl aldehydes has been achieved utilizing catalytic amounts of novel chiral ligands. Chiral ligands of amino alcohols and aminophosphine gave S-configured cyanosilylated products with up to 84% ee. In contrast, C2
An efficient catalytic asymmetric addition of trimethylsilyl cyanide to aldehydes at room temperature
Li, Zi-Bo,Rajaram, Amaresh R.,Decharin, Nattawan,Qin, Ying-Chuan,Pu, Lin
, p. 2223 - 2226 (2005)
The BINOL-salen compound (S)-5c in combination with Ti(O iPr)4 is found to catalyze the addition of TMSCN to aldehydes to form chiral cyanohydrins with very good enantioselectivity (75-85% ee). The reactions are carried out in one-pot at room temperature without the need to isolate the chiral Lewis acid catalyst.
Controlled Exchange of Achiral Linkers with Chiral Linkers in Zr-Based UiO-68 Metal-Organic Framework
Tan, Chunxia,Han, Xing,Li, Zijian,Liu, Yan,Cui, Yong
supporting information, p. 16229 - 16236 (2018/11/27)
The development of highly robust heterogeneous catalysts for broad asymmetric reactions has always been a subject of interest, but it remains a synthetic challenge. Here we demonstrated that highly stable metal-organic frameworks (MOFs) with potentially acid-labile chiral catalysts can be synthesized via postsynthetic exchange. Through a one- or two-step ligand exchange, a series of asymmetric metallosalen catalysts with the same or different metal centers are incorporated into a Zr-based UiO-68 MOF to form single- and mixed-M(salen) linker crystals, which cannot be accomplished by direct solvothermal synthesis. The resulting MOFs have been characterized by a variety of techniques including single-crystal X-ray diffraction, N2 sorption, CD, and SEM/TEM-EDS mapping. The single-M(salen) linker MOFs are active and efficient catalysts for asymmetric cyanosilylation of aldehydes, ring-opening of epoxides, oxidative kinetic resolution of secondary alcohols, and aminolysis of stilbene oxide, and the mixed-M(salen) linker variants are active for sequential asymmetric alkene epoxidation/epoxide ring-opening reactions. The chiral MOF catalysts are highly enantioselective and completely heterogeneous and recyclable, making them attractive catalysts for eco-friendly synthesis of fine chemicals. This work not only advances UiO-type MOFs as a new platform for heterogeneous asymmetric catalysis in a variety of syntheses but also provides an attractive strategy for designing robust and versatile heterogeneous catalysts.
