Acceptorless dehydrogenative construction of CN and CC bonds through catalytic aza-Wittig and Wittig reactions in the presence of an air-stable ruthenium pincer complex
aza-Wittig typereaction. The reaction is catalyzed by an acridine-derived ruthenium pincer complex and does not use any oxidant. The present protocol offers a wide substrate scope, including aliphatic, aryl or heteroaryl alcohol/azides. This expeditious protocol was successfully applied to construct a CC bond directly from alcohol via dehydrogenative Wittigreaction. Furthermore, the synthesis of structurally
C N键的构建是通过aza-Wittig型反应将醇与叠氮化物进行脱氢偶联而实现的。该反应由an啶衍生的钌钳配合物催化,并且不使用任何氧化剂。本协议提供了广泛的底物范围,包括脂族,芳基或杂芳基醇/叠氮化物。该快速方案已成功应用于通过脱氢Wittig反应直接从醇中构建C C键。此外,通过该方法还可以合成结构上重要的吡咯并[1,4]苯并二氮杂衍生物。
Indium mediated Barbier-type allylation of aldimines in alcoholic solvents
Barbier-type allylation of unactivated aldimines with allyl bromides in the presence of indium powder took place rapidly in alcoholic solvents to give homoallylic amines in fair to good yields.
Asymmetric Synthesis of<i>β</i>-Amino-<i>α</i>-Hydroxy Acids through Lewis Acid-Mediated Addition of Ketene Acetal to Imines
作者:Hyun-Joon Ha、Young-Gil Ahn、Jun-Sik Woo、Gwan Sun Lee、Won Koo Lee
DOI:10.1246/bcsj.74.1667
日期:2001.9
Asymmetric synthesis of β-amino-α-hydroxy acids, key components of medicinally important molecules including Paclitaxel, KRI-1314, amastatin, and microginin, has been attained from the aldimine coupling of chiral imines N-alkylidene-(S)- or (R)-α-methylbenzylamine with (Z)-α-methoxyketene methyltrimethylsilyl acetal, followed by demethylation, hydrogenolysis, and hydrolysis.
Anti-Markovnikov Addition of Both Primary and Secondary Amines to Terminal Alkynes Catalyzed by the TpRh(C<sub>2</sub>H<sub>4</sub>)<sub>2</sub>/PPh<sub>3</sub> System
Terminal alkynes react with secondaryamines in the presence of TpRh(C2H4)2/PPh3 (Tp = trispyrazolylborate) to give anti-Markovnikov E-enamines. Both Tp and PPh3 ligands are essential for the reaction. The reaction tolerates functional groups, such as ester, nitrile, and siloxy groups, on the terminal alkynes. Primaryamines also add to terminal alkynes in anti-Markovnikov fashion, yielding the corresponding