Transition Metal-Catalyzed Synthesis of Pyrroles from Dienyl Azides
摘要:
A range of 2,5-disubstituted and 2,4,5-trisubstituted pyrroles can be synthesized from dienyl azides at room temperature using catalytic amounts of Znl(2) or Rh-2(O2CC3F7)(4).
Cu/sulfoxide phosphine (SOP) complex catalyzed nucleophilic addition of fluorinated enolates to gem-difluoroalkenes. The enantioenriched vicinal difluorides, containing a chiral tertiary fluoride and a fluoroalkene, were successfully afforded via C–C bond formation in good yields (up to 94% yield), high Z/E-selectivity (5:1 → 50:1 for Z-isomer), and excellent enantioselectivities (up to 98.5:1.5 er). Utility
在这里,我们描述了第一个对映选择性 Cu/亚砜膦 (SOP) 配合物催化氟化烯醇化物与偕二氟烯烃的亲核加成。含有手性叔氟化物和氟代烯烃的对映体富集的连二氟化物通过 C-C 键的形成成功地提供了良好的产率(高达 94% 的产率),高Z / E选择性(5:1 → 50:1 for Z -异构体)和出色的对映选择性(高达 98.5:1.5 er)。通过对复杂的生物活性化合物的修饰证明了这种方法的实用性。
Organocatalytic Asymmetric Michael-Hemiacetalization Reaction Between 2-Hydroxyacetophenones and Enals: A Route to Chiral β,γ-Disubstituted γ-Butyrolactones
作者:Megha Balha、Buddhadeb Mondal、Subas Chandra Sahoo、Subhas Chandra Pan
DOI:10.1021/acs.joc.7b00363
日期:2017.6.16
The first highlyenantioselective organocatalytic reaction employing 2-hydroxyacetophenones is disclosed, namely Michael-hemiacetalization reaction of 2-hydroxyacetophenones with enals. The combination of a primaryamine and a secondaryaminecatalyst was found to be the best choice for this methodology. The products of this reaction were obtained in high enantio- and diastereoselectivities and were
Diarylprolinol‐Mediated Asymmetric Direct Cross‐Aldol Reaction of α,β‐Unsaturated Aldehyde as an Electrophilic Aldehyde
作者:Yujiro Hayashi、Kaito Nagai、Shigenobu Umemiya
DOI:10.1002/asia.201901236
日期:2019.12.2
The diarylprolinol-mediated asymmetric direct cross-aldol reaction of α,β-unsaturated aldehyde as an electrophilic aldehyde was developed. The reaction becomes accelerated by an acid when a carbonyl group is introduced at the γ-position of the α,β-unsaturated aldehyde. Synthetically useful γ,δ-unsaturated β-hydroxy aldehydes were obtained with high anti-selectivity and excellent enantioselectivity
The present invention relates to the following phenylalanine derivatives or analogues thereof having an antagonistic activity to α4 integrin and therapeutic agents for various diseases concerning α4 integrin.
Specified phenylalanine derivatives and analogues thereof have an antagonistic activity to α4 integrin. They are used as therapeutic agents for various diseases concerning α4 integrin.