比较开链仲,仲-1,2-二醇的双-(R)-或双-(S)-MPA酯衍生物的室温和低温1 H NMR光谱,可轻松确定其相对立体化学,有时甚至是绝对构型。如果二醇是抗性的,则其绝对构型可以直接从ΔδT1T2的符号推导出对于取代基R 1 / R 2,但如果二醇的相对立体化学是顺式,则其绝对构型的分配需要制备两种衍生物(双-(R)-和双-(S)-MPA酯) ,其室温的比较1 1 H NMR谱,并计算该Δδ的RS次甲基Hα(R 1)和Hα(R 2)和R 1 / R 2质子的符号。这些相关性的可靠性通过用作模型化合物的已知绝对构型的17种二醇进行了验证。
anti-Selective aldol reactions of chiral alcohol substituted γ-benzyloxyl vinylogous urethanes and the synthesis of 3-benzyloxyl-4-hydroxylalkan-2-ones
摘要:
The anti-selective aldol reaction of chiral alcohol-substituted gamma-benzyloxy vinylogous urethanes is described. The use of (1S,2R,4R)-1-(hydroxydiphenylmethyl)-7,7-dimethylbicyclo[2,2,1]-heptan-2-ol as a chiral auxiliary in the aldol reaction of a vinylogous urethane enolate was found to provide anti-products in good yields with moderate to excellent enantioselectivities. The major anti-vinylogous urethane lactones were transformed into 3-benzyloxyl-4-hydroxylalkan-2-ones in good yields. (C) 2017 Elsevier Ltd. All rights reserved.
The present disclosure provides pyridines and pyrimidines of Formula I and pharmaceutically acceptable salts and solvates thereof: wherein A, G, W
1
, W
2
, W
3
, and R
5
are defined as set forth in the specification. The present disclosure also provides uses of the compounds of Formula I and pharmaceutically acceptable salts and solvates thereof. In certain embodiments, Compounds of the present disclosure are useful for treating pain. In another embodiment, Compounds of the present disclosure are useful for treating a disorder responsive to blockade of sodium channels, or alleviating symptoms of the disorder.
water-compatible amino-acid-based catalysts was explored in the development of diastereo- and enantioselectivedirectaldolreactions of a broad range of substrates. Chiral C2-symmetrical proline- and valine-based amides and their ZnII complexes were designed for use as efficient and flexible chiral catalysts for enantioselectivealdolreactions in water, on water, and in the presence of water. The presence of
The aldolreaction of hydroxyacetone with different aldehydes usingimmobilizedproline on a mesoporoussupport, assisted by heat and microwaves, has been explored. It was found that heterogenized L-proline on MCM-41 catalyzed aldolreactions in both hydrophilic and hydrophobic solvents, and provided stereoselectivities in some cases complementary to the homogeneous catalyst. The heterogeneous catalysts
The Invention provides indole derivatives of Formula I:
and pharmaceutically acceptable salts and solvates thereof, wherein R
1e
, R
1f
, A, X, Y, Z, and W
4
are defined as set forth in the specification. The Invention also provides the use of compounds of Formula I and the pharmaceutically acceptable salts and solvates thereof to treat pain. In certain embodiments, the Compounds of the Invention are effective in treating a disorder responsive to blockade of one or more sodium channels.
Amino Acid Catalyzed Direct Asymmetric Aldol Reactions: A Bioorganic Approach to Catalytic Asymmetric Carbon−Carbon Bond-Forming Reactions
作者:Kandasamy Sakthivel、Wolfgang Notz、Tommy Bui、Carlos F. Barbas
DOI:10.1021/ja010037z
日期:2001.6.1
lack of nonlinear effects. The reactions tolerate a small amount of water (<4 vol %), do not require inert reaction conditions and preformed enolate equivalents, and can be conveniently performed at room temperature in various solvents. In addition, reaction conditions that facilitate catalyst recovery as well as immobilization are described. Finally, mechanistically related addition reactions such as