Provided herein are compounds of the formula (I):
as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of metabolic diseases and disorders such as, for example, type II diabetes mellitus.
(NDI core substituents: SO2R>SOR>H>OR>OR/NR2>SR>NR2). The H–D exchange kinetics vary with the structure of the enolate (malonates>methylmalonates, dilactones>dithiolactones). Moreover, they depend on the distance to the π surface (bridge length: 11–13 atoms). Most importantly, H–D exchange depends strongly on the chirality of the π surface (chiral sulfoxides as core substituents; the crystal structure
烯醇式化学在化学和生物学中具有至关重要的意义,是阐述阴离子-π相互作用对催化的可能贡献的一个有吸引力的话题。为了证明这种贡献的存在,决定性的不仅是阴离子,而且是阴离子中间体和π-酸性芳香族表面上过渡态的稳定化的实验证据。为了以最大的精度和最小的不确定性应对烯醇化学的这一挑战,丙二酸二内酯共价位于萘二酰亚胺(NDI)的π-酸性表面上。它们的存在在1中的α-质子的高场位移中直接可见1 H NMR谱。这些质子在π酸性表面上的反应性是通过氢-氘(H-D)交换测量的,用于11个不同的实例(不包括对照)。H-D交换的速度随π酸度的增加而增加(NDI核取代基:SO 2 R> SOR> H> OR> OR / NR 2 > SR> NR 2)。H-D交换动力学随烯醇化物的结构而变化(丙二酸酯>甲基丙二酸酯,双内酯>二硫代内酯)。而且,它们取决于到π表面的距离(桥的长度:11-13个原子)。最重要的是,H-
Direct Catalytic Asymmetric Mannich Reaction with Dithiomalonates as Excellent Mannich Donors: Organocatalytic Synthesis of (<i>R</i>)-Sitagliptin
作者:Han Yong Bae、Mun Jong Kim、Jae Hun Sim、Choong Eui Song
DOI:10.1002/anie.201605167
日期:2016.8.26
enantioselectivity (up to 99 % ee). Furthermore, by the use of a DTM, even some highly challenging primary alkyl α‐amidosulfones were smoothly converted into the desired adducts with excellent enantioselectivity (up to 97 % ee), whereas the use of a malonate or monothiomalonate resulted in no reaction under identical conditions. The synthetic utility of the chiral Mannich adducts obtained from primary alkyl substrates
A series of novel l-proline derived tertiary amine bifunctional organocatalysts 9 are reported, which were applied to the asymmetric Michaeladdition of dithiomalonates 2 to trans-β-nitroolefins 1. The reaction proceeded in high yields (up to 99%) with high enantioselectivities (up to 97% ee). The synthetic utility of this methodology was demonstrated in the short synthesis of (R)-phenibut in high
Water-Enabled Catalytic Asymmetric Michael Reactions of Unreactive Nitroalkenes: One-Pot Synthesis of Chiral GABA-Analogs with All-Carbon Quaternary Stereogenic Centers
作者:Jae Hun Sim、Choong Eui Song
DOI:10.1002/anie.201611466
日期:2017.2.6
new catalytic reactions for otherwise unreactive substrate systems. Under the “on water” reaction conditions, extremely unreactive β,β‐disubstituted nitroalkenes smoothly underwent enantioselective Michael addition reactions with dithiomalonates using a chiral squaramide catalyst, affording both enantiomers of highly enantioenriched Michael adducts with all‐carbon‐substituted quaternarycenters. The