Palladium(II)-Catalyzed Cyclization Using Molecular Oxygen as Reoxidant
摘要:
A Palladium(II)-catalyzed intramolecular allylic oxidation using nitrogen and oxygen nucleophiles and molecular oxygen as reoxidant has been developed.
Oxidative Cyclizations in a Nonpolar Solvent Using Molecular Oxygen and Studies on the Stereochemistry of Oxypalladation
作者:Raissa M. Trend、Yeeman K. Ramtohul、Brian M. Stoltz
DOI:10.1021/ja055534k
日期:2005.12.1
illustrates the range of reactivity available from various Pd(II) salts under differing conditions. Alcohols can form both fused and spirocyclicring systems, depending on the position of the olefin relative to the tethered alcohol; the same is true of the acid derivatives. The racemic conditions served as a platform for the development of an enantioselective reaction. Experiments with stereospecifically
在非极性溶剂(甲苯)中,在分子氧作为唯一化学计量氧化剂的存在下,钯 (II) 和吡啶催化各种杂原子亲核试剂氧化环化到未活化的烯烃上。许多 N-连接的钯配合物的反应性研究表明螯合配体减慢反应。几乎相同的条件适用于五种不同类型的亲核试剂:酚类、伯醇、羧酸、乙烯酸和酰胺。富电子酚类是极好的底物,并且可以容忍多种烯烃取代模式。伯醇会发生氧化环化反应而没有明显氧化成醛,这一事实说明了在不同条件下可从各种 Pd(II) 盐获得的反应性范围。醇可以形成稠环和螺环系统,这取决于烯烃相对于束缚醇的位置;酸衍生物也是如此。外消旋条件作为发展对映选择性反应的平台。立体定向氘代伯醇底物的实验排除了涉及抗氧化钯的“Wacker 型”机制,并表明该反应通过单齿和双齿配体的同步氧化钯进行。相比之下,氘标记的羧酸底物的环化会发生抗氧化钯。立体定向氘代伯醇底物的实验排除了涉及抗氧化钯的“Wacker 型”机制,并表明该反应
Organoselenium-induced cyclizations in organic synthesis
作者:K.C. Nicolaou
DOI:10.1016/s0040-4020(01)93285-5
日期:——
A number of organoselenium reagents are introduced as efficient initiators of ringclosures leading from unsaturated substrates to lactones, cyclicethers, cyclic thioethers, N-heterocycles and carbocycles. These cyclizations often proceed with high ring selectivity and stereoselectivity and are accompanied by the incorporation of the phenylseleno group (PhSe) into the final product. Methods are described
Enantio‐ and Diastereoselective Suzuki–Miyaura Coupling with Racemic Bicycles
作者:F. Wieland Goetzke、Mike Mortimore、Stephen P. Fletcher
DOI:10.1002/anie.201906478
日期:2019.8.26
Herein, we describe a rhodium‐catalyzed enantio‐ and diastereoselective Suzuki–Miyaura cross‐coupling between racemic fused bicyclic allylic chlorides and boronic acids. The highly stereoselective transformation allows for the coupling of aryl, heteroaryl, and alkenyl boronic acids and gives access to functionalized bicyclic cyclopentenes, which can be converted into other five‐membered‐ring scaffolds
Phenylselenoetherification. A highly efficient cyclization process for the synthesis of oxygen- and sulfur-heterocycles
作者:K. C. Nicolaou、R. L. Magolda、W. J. Sipio、W. E. Barnette、Z. Lysenko、M. M. Joullie
DOI:10.1021/ja00531a020
日期:1980.5
Palladium(II)-Catalyzed Cyclization Using Molecular Oxygen as Reoxidant
作者:Magnus Rönn、Jan-E. Bäckvall、Pher G. Andersson
DOI:10.1016/0040-4039(95)01616-p
日期:1995.10
A Palladium(II)-catalyzed intramolecular allylic oxidation using nitrogen and oxygen nucleophiles and molecular oxygen as reoxidant has been developed.