[反应:见正文]描述了由普通的多元醇中间体实际合成全酰胺B,E和Z。连续的醛醇缩合提供适合于与双酰胺偶联的保护的多元醇硫酯侧链。新型手性相转移催化的对映选择性烷基化反应提供了Bengamides B和Z所需的功能更高的氨基己内酰胺。使用2-萘甲基甲醚保护基与对映选择性羟醛缩合所需的硼Lewis酸相容,可直接获得Bengamide B 。
One-Pot Tandem 1,4- and 1,2-Addition of Phosphites to α,β-Unsaturated Hydrazones
作者:Christian Stevens、Ellen Van Meenen、Kurt Masschelein、Kristof Moonen、Ann De Blieck、Jozef Drabowicz
DOI:10.1055/s-2007-986654
日期:2007.10
The 1,4- and 1,2-addition of phosphites to α,β-unsaturated hydrazones was investigated. When silylated phosphites and trialkyl phosphites were compared, trialkyl phosphites gave better conversions and subsequently higher yields. A variety of hydrazones were evaluated as substrate in this reaction, which yield 3-phosphonyl-1-hydrazinoalkyl phosphonates.
Access to Triazolopiperidine Derivatives via Copper(I)‐Catalyzed [3+2] Cycloaddition/Alkenyl C−N Coupling Tandem Reactions
作者:Guorong Xiao、Kaifu Wu、Wei Zhou、Qian Cai
DOI:10.1002/adsc.202100955
日期:2021.11.9
A copper-catalyzed [3+2] cylcoaddition/ alkenyl C−N coupling tandem reaction was demonstrated. It provided a method for the formation of triazolopiperidine skeletons.
first highly enantioselective and regiodivergent conjugate addition of trialkylaluminium reagents to nitrodienes and nitroenynes is described. By a design of the substrate and a fine-tuning of the reaction conditions, it is possible to selectively form the 1,4- or 1,6-adduct. The same combination of catalyst, copper source, and a ferrocene-based phosphine ligand afforded enantioselectivities up to 95%
Enantio- and Regioselective Conjugate Addition of Organometallic Reagents to Linear Polyconjugated Nitroolefins
作者:Matthieu Tissot、Alexandre Alexakis
DOI:10.1002/chem.201300538
日期:2013.8.19
The copper‐catalysed conjugate addition of trialkylaluminium and dialkylzinc reagents to polyconjugated nitroolefins (nitrodiene and nitroenyne derivatives) is reported. A reversed Josiphos ligand L7 allows for the selective 1,4‐ or 1,6‐addition with high enantioselectivities.
We describe the characterisation of the O-methyltransferase JerF from the late stages of jerangolid biosynthesis. JerF is the first known example of an enzyme that catalyses the formation of a non-aromatic, cyclic methylenolether. The enzyme was overexpressed in E. coli and the cell-free extracts were used in bioconversion experiments. Chemical synthesis gave access to a series of substrate surrogates