Asymmetric Formal [3+2] Cycloaddition Reaction of Isocyanoesters to 2‐Oxobutenoate Esters by a Multifunctional Chiral Silver Catalyst
作者:Jin Song、Chang Guo、Peng‐Hao Chen、Jie Yu、Shi‐Wei Luo、Liu‐Zhu Gong
DOI:10.1002/chem.201100636
日期:2011.7.4
Silver‐standard selectivity! The first highly enantioselective formal [3+2] cycloaddition reaction of isocyanoesters with 2‐oxobutenoate esters catalyzed by a chiralsilver complex proceeded readily under the catalysis of a multifunctional chiralsilver complex in high yields and enantiometric excess (ee) values of up to 98 % (see scheme).
Highly enantioselective Michael addition of malonates to β,γ-unsaturated α-ketoesters catalyzed by chiral N,N′-dioxide-Yttrium(iii) complexes with convenient procedure
HighlyenantioselectiveMichaeladdition of malonates to beta,gamma-unsaturated alpha-ketoesters has been promoted by chiral N,N'-dioxide-Yttrium(iii) complexes, providing the corresponding products in excellent yields with 94-99% ee values.
Asymmetric Diels–Alder and Inverse‐Electron‐Demand Hetero‐Diels–Alder Reactions of β,γ‐Unsaturated α‐Ketoesters with Cyclopentadiene Catalyzed by
<i>N</i>
,
<i>N</i>
′‐Dioxide Copper(II) Complex
Highlyenantioselective Diels–Alder (DA) and inverse‐electron‐demand hetero‐Diels–Alder (HDA) reactions of β,γ‐unsaturated α‐ketoesters with cyclopentadiene catalyzed by chiral N,N′‐dioxide–Cu(OTf)2 (Tf=triflate) complexes have been developed. Quantitative conversion of β,γ‐unsaturated α‐ketoesters and excellent diastereoselectivities (up to 99:1) and enantioselectivities (up to >99 % ee) were observed
A three-component reaction of β,γ-unsaturated α-keto esters, proline, and dialkyl maleates has been developed. This reaction provides pyrrolizidine derivatives containing three ester groups and a styrenyl group, as well as a quaternary center, in moderate to good yields and with good to excellent diastereoselectivities.
Asymmetric Michael addition between kojic acid derivatives and unsaturated ketoesters promoted by <i>C</i><sub>2</sub>-symmetric organocatalysts
作者:Alexey A. Kostenko、Alexander S. Kucherenko、Andrey N. Komogortsev、Boris V. Lichitsky、Sergei G. Zlotin
DOI:10.1039/c8ob02523a
日期:——
An efficient sterically hindered C2-symmetric bifunctionaltertiary amine–squaramide organocatalyst for the asymmetric Michaeladdition/hemiketalization domino reaction of kojic acid derivatives with β,γ-unsaturated α-ketoesters has been designed. Pharmacology-relevant functionalized 2,3,4,8-tetrahydropyrano[3,2-b]pyran derivatives were produced over the catalyst in as low as 1 mol% with up to 99%
设计了一种高效的位阻C 2对称双官能叔胺-方酰胺有机催化剂,用于曲酸衍生物与β,γ-不饱和α-酮酸酯的不对称迈克尔加成/半缩酮化多米诺反应。在催化剂上以低至1 mol%的产率制备了药理学相关的官能化2,3,4,8-四氢吡喃并[3,2- b ]吡喃衍生物,产率高达99%,ee高达99%。该程序至少可扩展30倍,并且该催化剂可通过酸碱萃取容易地用于催化反应中。用(S)-或rac酰化产物-布洛芬和十一碳烯酸与相应的手性酯含有两个特权药效基序。