The object of the present invention is to provide a compound and a pharmaceutical composition having excellent Syk inhibitory activity. According to the present invention, a nicotinamide derivative represented by the following formula (I) or a salt thereof is provided,
wherein
R
1
is a substituent represented by the following formula (II-1), (III-1), or (IV-1)
(wherein R
3
, R
4
, R
5
, n, and X
1
have the same definitions as those described in the specification), and R
2
is a pyridyl, indazolyl, phenyl, pyrazolopyridyl, benzisoxazolyl, pyrimidinyl, or quinolyl group, each of which optionally has at least one substituent.
Titanium Salalen Catalysts Based on<i>cis</i>-1,2-Diaminocyclohexane: Enantioselective Epoxidation of Terminal Non-Conjugated Olefins with H<sub>2</sub>O<sub>2</sub>
Help for the neglected: Terminal, non‐conjugated olefins, such as 1‐octene, are difficult to epoxidize asymmetrically. Ti salalen complexes based on cis‐1,2‐diaminocyclohexane catalyze this demanding reaction giving high yields and enantioselectivities (up to 95 % ee), with H2O2 as the oxidant. The X‐ray structures of the μ‐oxo and peroxocomplexes shed light on the coordination behavior of this novel
被忽视的帮助:末端非共轭烯烃(例如1-辛烯)难以不对称环氧化。基于顺式1,2-二氨基环己烷的Ti salalen络合物以H 2 O 2为氧化剂,可催化要求苛刻的反应,从而提供高收率和对映选择性(最高95% ee)。μ-oxo和peroxo配合物的X射线结构阐明了这类新型配体的配位行为。
Competing Hydrogen-Bond Polarities in a Dynamic Oligourea Foldamer: A Molecular Spring Torsion Balance
作者:Romina Wechsel、Matej Žabka、John W. Ward、Jonathan Clayden
DOI:10.1021/jacs.8b00567
日期:2018.3.14
guests (acetate or phosphate, but not neutral hydrogen-bonding solvents) leads to inversion of the conformational preference, as strong intermolecular hydrogen bonding induces reorganization of the intramolecularhydrogen-bond network. The foldamers behave as a molecular torsion balance whose conformational preference is governed by competing hydrogen-bond pairing.
Kinetic Resolution of 5-Substituted Oxazinones with Bifunctional Chiral Base/Squaramide Organocatalysts
作者:Albrecht Berkessel、Serap Eröksüz、Jörg Neudörfl
DOI:10.1055/s-0036-1588852
日期:2017.7
5-Substituted oxazinones provide N-protected β2-amino acid esters upon alcoholytic ring opening. Thus far, this access to enantiopure β2-amino acids has been restricted to the use of enzymes (hydrolases) as catalysts for the kineticresolution of racemic 5-substituted oxazinones, and branched alkyl or ortho-substituted aryl groups on the substrate oxazinone’s 5-position were typically not tolerated
desymmetrized monomer 2. Despite being achiral, the meso oligomers adopt chiral canonical 2.5‐helical conformations, the equally populated enantiomeric screw‐sense conformers of which are in slow exchange on the NMR timescale, with a barrier to screw‐sense inversion of about 70 kJ mol−1. Screw‐sense inversion in these helical foldamers is coupled with cyclohexane ring‐flipping, and results in a reversal