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.
Palladium-Catalyzed Oxidative Borylative Carbocyclization of Enallenes
作者:Andreas K. Å. Persson、Tuo Jiang、Magnus T. Johnson、Jan-E. Bäckvall
DOI:10.1002/anie.201008032
日期:2011.6.27
An efficient oxidative carbocyclization/borylation of enallenes uses Pd(OAc)2 as the catalyst, B2pin2 as the boron‐transfer reagent, and 1,4‐benzoquinone (BQ) as the oxidant (see scheme). The reaction seems to take place through activation of the allene by a PdII complex to give an alkenyl–PdII intermediate followed by carbopalladation of the olefin and subsequent cleavage of the intermediate palladium–carbon
Carbon−Carbon Bond Formation in Palladium(II)-Catalyzed Allylic Oxidation: A Novel Oxidative Carbocyclization of Allene-Substituted Olefins
作者:Johan Franzén、Jan-E. Bäckvall
DOI:10.1021/ja029505a
日期:2003.5.1
efficient palladium(II)-catalyzedoxidativecarbocyclization has been developed. It was found that allene-substituted olefins 1 cyclized in the presence of 1 mol % Pd(O2CCF3)2 and p-benzoquinone (2 equiv) to give bicyclic ring systems 2 in good to excellent yields. The cyclization constitutes a new type of carbon-carbon bond forming reaction between an allene and an olefin under oxidative conditions
New Phosphite−Oxazoline Ligands for Efficient Pd-Catalyzed Substitution Reactions
作者:Oscar Pàmies、Montserrat Diéguez、Carmen Claver
DOI:10.1021/ja0425738
日期:2005.3.1
synthesized a new family of readily available highly modularphosphite-oxazolineligands for the Pd-catalyzedasymmetric allylic substitution reactions. The introduction of a pi-acceptor flexible bulky biphenyl phosphite moiety in the ligand design is highly adventitious in the product outcome. Thus, this ligand series affords excellent reaction rates (TOF's up to >2400 mol.(mol.h)-1) and enantioselectivities
我们设计并合成了一系列易于使用的高度模块化的亚磷酸酯-恶唑啉配体,用于 Pd 催化的不对称烯丙基取代反应。在配体设计中引入 pi 受体柔性庞大的亚磷酸联苯部分在产品结果中是非常偶然的。因此,该配体系列提供了出色的反应速率(TOF 高达 >2400 mol.(mol.h)-1)和对映选择性(ee 高达 >99%),同时显示出适用于不同底物类型的广泛范围.
Palladium-catalyzed asymmetric allylic alkylations of cycloalkenyl acetates with planar chiral phosphino-ferrocene carboxylic acids
作者:Shu-Li You、Yu-Mei Luo、We-Ping Deng、Xue-Long Hou、Li-Xin Dai
DOI:10.1016/s0022-328x(01)01143-3
日期:2001.12
Abstract New phosphino-ferrocene carboxylicacids with only planar chirality ( Sp )- 3 and ( Sp )- 4 have been synthesized conveniently from ( S , Sp )- 5 and ( S , Sp )- 7 . They were used as ligands in palladium-catalyzedallylicalkylation of cycloalkenyl acetates. With ligand ( Sp )- 4 , high yield and good ee were given for reactions of a series of cycloalkenyl acetates and nucleophiles.
The chiral diphosphine ligand xylophos (1) was tested as an auxiliary in palladium catalyzed allylic substitution reactions. Whereas its activity was found to be generally good only in the case of 1,3-diphenylprop-2-en-1-yl acetate, a fair level of asymmetric induction was achieved with sodium dimethyl malonate (83% ee) and benzylamine (66% ee) as nucleophiles.