97358-11-7Relevant academic research and scientific papers
o-Trityl phenoxy-imino vanadium (III) complexes: synthesis, characterization, and catalysis on ethylene (co)polymerization
Hao, Zhiqiang,Li, Feng,Gao, Wei
, (2020)
Several phenoxy-imine ligands bearing o-trityl group in phenoxy moiety RN=CHArOH (Ar = C6H2(CPh3)tBu, R = 2,6-Me2C6H3 (L1H); 2,6-iPr2C6/sub
Stereoselective protonation of 2-methyl-1-tetralone lithium enolate catalyzed by salan-type diamines
?owicki, Daniel,Watral, Justyna,Jelecki, Maciej,Bohusz, Wiktor,Kwit, Marcin
supporting information, (2021/04/02)
Asymmetric protonation of ketone enolates is a convenient alternative to asymmetric alkylation of enolates that allows to convert racemic ketones into their optically active form. Here, we have reported an efficient enantioselective protonation of 2-methyl-1-tetralone lithium enolate catalyzed by salan-type diamines. A broad series of salan-type catalysts were synthesized, including several previously unknown, and subsequently tested in the title reaction. For the first time, a chiral amine used as organocatalyst has shown better results than as stoichiometric protonating agent. Application of only 10 mol% of salan allows to obtain the title ketone with high yield and enantiomeric excess up to 75%. The DFT calculations of the structure of the catalyst and its complex with lithium enolate were conducted, which makes it possible to propose a likely reaction mechanism.
Synthesis of chiral salan ligands with bulky substituents and their application in Cu-catalyzed asymmetric Henry reaction
He, Jianghao,Mu, Ying,Wang, Zhou
, (2020/10/09)
Several new chiral N,N’-dimethylated salan ligands with bulky substituents were synthesized and their in-situ generated Cu(II) complexes were evaluated in the asymmetric Henry reaction. Substituents on the aryloxide moieties of these ligands were found to
Tritylated alkyl aryl ethers
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Paragraph 0012; 0013; 0014; 0015, (2016/10/09)
A compound having formula (Ph3C)mAr(R1)j(OR2)n, wherein Ph represents a phenyl group, Ar is an aromatic ring system having from six to twenty carbon atoms, R1 and R2 independently are C1-C18 alkyl or C4-C18 heteroalkyl, m is one or two, j is an integer from one to four and n is an integer from one to three.
Highly Enantioselective Epoxidation of α,β-Unsaturated Ketones Catalyzed by Rare-Earth Amides [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 with Phenoxy-Functionalized Chiral Prolinols
Zeng, Chao,Yuan, Dan,Zhao, Bei,Yao, Yingming
supporting information, p. 2242 - 2245 (2015/05/13)
A simple and efficient catalytic enantioselective epoxidation of α,β-unsaturated ketones has been successfully developed, which was catalyzed by rare-earth metal amides [(Me3Si)2N]3RE(μ-Cl)Li(THF)3 (RE = Yb (1), La (2), Sm (3), Y (4), Lu (5)) in the presence of phenoxy-functionalized chiral prolinols at room temperature using tert-butylhydroperoxide (TBHP) as the oxidant. The combination of an Yb-based amide 1 and a chiral proligand (S)-2,4-di-tert-butyl-6-((2-(hydroxydiphenylmethyl)pyrrolidin-1-yl)methyl)phenol) performed very well, and both the yields and the enantiomeric excess of the chiral epoxides reached up to 99% and 99% ee. (Figure Presented).
Co-metal-free enantioselective conjugate addition reactions of zinc reagents
Ay, Sefer,Nieger, Martin,Braese, Stefan
experimental part, p. 11539 - 11556 (2009/12/07)
Asymmetric conjugate addition of diethylzinc to cinnamaldehyde in a co-metal-free fashion by using N,O-ligands with planar and central chirality is described. Different modulations of the ligand structure, including several combinations of the chiral units, indicate that a [2.2]paracyclophane backbone is essential for the activity and the enantioselectivity of the generated active catalyst. By using the optimized ligand, an isolated yield of 90 % was obtained with up to 99 % ee.
Synthesis of salicylaldehydes bearing bulky substituents in the positions 3 and 5
Kochnev,Oleynik,Oleynik,Ivanchev,Tolstikov
, p. 1125 - 1129 (2008/09/17)
Reaction of 2,4-disubstituted phenols with paraformaldehyde in the presence of SnCl4 and 2,6-lutidine afforded a number of new salicylaldehydes, containing bulky substituents (tert-butyl, 1-phenylethyl, 1-(4-tert- butylphenyl)ethyl, α-cumyl, and trityl) in the positions 3 and 5.
