本文描述了苔藓抑素环 A 和 B 亚基立体选择性组装的化学选择性和原子经济方法。钌催化的串联烯烃-炔耦合/迈克尔加成反应的开发和应用到苔藓抑素环B的合成我们探讨乙炔化介导的环氧化物的开/ 6-外型-挖环化路径访问的苔藓抑素环A,虽然环 A 最终通过酸催化的串联转缩酮/缩酮化序列提供。此外,还评估了双核锌催化甲基乙烯基酮(MVK)羟醛策略用于构建聚乙酸酯部分。这些方法的使用最终导致了包含环 A 和 B 亚基的北部苔藓抑素片段的快速组装。
Bis(trimethylsilyl) peroxide (BTSP) serves as an effective oxidant of alcohols in the presence of chromium(VI) or ruthenium(II) complexes as catalysts in dichloromethane. Selective oxidation of primary alcohols in preference to secondary ones using RuCl2(PPh3)3 as a catalyst is also described.
Synthesis of <i>Z</i>-Alkenes from Rh(I)-Catalyzed Olefin Isomerization of β,γ-Unsaturated Ketones
作者:Lian-Gang Zhuo、Zhong-Ke Yao、Zhi-Xiang Yu
DOI:10.1021/ol401607c
日期:2013.9.20
Developing olefin isomerization reactions to reach kinetically controlled Z-alkenes is challenging because formation of trans-alkenes is thermodynamically favored under the traditional catalytic conditions using acids, bases, or transition metals as the catalysts. A new synthesis of Z-alkenes from Rh(I)-catalyzed olefin isomerization of β,γ-unsaturated ketones to α,β-unsaturated ketones was developed
Dienamine-Mediated Asymmetric Inverse-Electron-Demand Hetero-Diels-Alder Reaction of Linear Deconjugated Enones: Diversity-Oriented Synthesis of 3,4-Dihydropyrans
作者:Rajendra Maity、Subhas Chandra Pan
DOI:10.1002/ejoc.201601575
日期:2017.1.26
The dienamine‐mediated inverse‐electron‐demandhetero‐Diels–Alderreaction of deconjugated enones having α‐CH groups and electron‐deficient oxadienes with a cyano group allows the efficient and enantioselectivesynthesis of 2,4‐stereogenic 3,4‐dihydropyrans. With a primary amine and benzoic acid, high yields and excellent enantioselectivities are obtained for a range of 3,4‐dihydropyrans.
Green Organocatalytic Synthesis of Isoxazolines via a One-Pot Oxidation of Allyloximes
作者:Ierasia Triandafillidi、Christoforos G. Kokotos
DOI:10.1021/acs.orglett.6b03380
日期:2017.1.6
A green, sustainable, organocatalytic, and efficient synthesis of isoxazolines from allyloximes was developed. A 2,2,2-trifluoroacetophenone-catalyzed oxidation of allyloximes, utilizing H2O2 as the green oxidant, was taken advantage of in order to introduce a cheap and environmentally friendly protocol for the synthesis of substituted isoxazolines. A variety of substitution patterns, both aromatic
从烯丙基肟开发了一种绿色,可持续,有机催化和高效的异恶唑啉合成方法。利用H 2 O 2作为绿色氧化剂,利用2,2,2-三氟苯乙酮催化的烯丙基肟的氧化反应,以引入廉价且环境友好的方法合成取代的异恶唑啉。芳香族和脂肪族部分的各种取代方式都具有良好的耐受性,从而导致异恶唑啉的产率中等至优异。
The first chemoenzymatic total synthesis of the phytotoxic nonenolide putaminoxin and its (5S,6E,9S)-diastereomer
to a valuable building block for the total synthesis of phytotoxicnonenolideputaminoxin. The enzymatic approach towards the enantioenriched homoallylic alcohol was compared to classical, nonenzymatic approaches using asymmetric reagent controlled allyl additions and the obtained building block was used for the total synthesis of putaminoxin and its (5S,6E,9S)-diastereomer. After the spectroscopic