Copper-Catalyzed Asymmetric Conjugate Addition of Trialkylaluminium Reagents to Trisubstituted Enones: Construction of Chiral Quaternary Centers
作者:Magali Vuagnoux-d'Augustin、Alexandre Alexakis
DOI:10.1002/chem.200701001
日期:2007.11.26
vinylalane species undergo enantioselective conjugateaddition to a wide range of 2- or 3-substituted enones (cyclopent-2-enones, cyclohex-2-enones, 3-methyl cyclohept-2-enone) in the presence of catalytic amount of copper salt (copper thiophene carboxylate, [Cu(CH3CN)4]BF4 or [CuOTf]2C6H6) and tropos-phosphoramidite-based ligand. Thus, chiral quaternarycenters can be built, with up to 98% ee after rigorous
Formation of Contiguous Quaternary and Tertiary Stereocenters by Sequential Asymmetric Conjugate Addition of Grignard Reagents to 2-Substituted Enones and Mg-Enolate Trapping
作者:Nicolas Germain、Alexandre Alexakis
DOI:10.1002/chem.201500292
日期:2015.6.1
tolerated for the ACA to 2‐methylcyclohexenone. The sequential ACA–enolate trapping, which leads to quaternarystereocenters, was then studied. Thus, many electrophiles have been tested, thereby giving rise to highly functionalized cyclic ketones with contiguous α‐quaternary and β‐tertiary centers. The present technique is believed to bring a new approach to versatile terpenoid‐like skeletons of bioactive
In the presence of a Cu(I)N-monosubstituted sulfonamide combined catalyst system, diorganozincs react with α,β-unsaturated ketones to generate Zn enolates, which may be hydrolyzed, giving the β-substituted ketones, or used for further aldol reaction or Pd(0)-catalyzed reaction with allyl acetate leading to the regiospecific α,β-vicinal condensation products.
Low-pollution antidegradant compound and antidegradant composition and rubber composition comprising the same for tires
申请人:Sennics Co., Ltd.
公开号:US11008281B2
公开(公告)日:2021-05-18
Antidegradant compound of Formula I:
and antidegradant composition comprising the same and rubber composition comprising the antidegradant compound or composition. The rubber composition has good resistance to appearance discoloration while maintaining the mechanical and anti-aging properties, thus, are suitable for making the entire tire or as part of the rubber matrix.