作者:Basker Sundararaju、Mathieu Achard、Bernard Demerseman、Loic Toupet、Gangavaram V. M. Sharma、Christian Bruneau
DOI:10.1002/anie.200907034
日期:2010.4.1
Branching out: A new ruthenium(IV) complex (1), containing a P,O‐chelating ligand, is an efficient precatalyst for regioselective allylations starting from various allylicalcohol derivatives.
The synthesis of the new complexes [Ru(Cp*)(L)(MeCN)2][PF6] (L = Ph2POMe or Ph2P-o-tolyl) and Ru(Cp*)[Ph2PCH2C(tBu)=O](MeCN)}[PF6] (2a–c) is achieved starting from [Ru(Cp*)(MeCN)3][PF6]. The acetonitrile ligands in complexes 2a–c are labile, as emphasised by the easy formation of Ru(Cp*)(CO)2[Ph2PCH2C(=O)tBu]}[PF6] (3). The keto-phosphane is used as a tool to convert 3 into Ru(Cp*)(CO)[Ph2PCH2C(tBu)=O]}[PF6]
Ruthenium-CatalyzedO-Allylation of Phenols from Allylic Chloridesvia Cationic[Cp*(η3-allyl)(MeCN)RuX][PF6] Complexes
作者:Mbaye D. Mbaye、Bernard Demerseman、Jean-Luc Renaud、Loïc Toupet、Christian Bruneau
DOI:10.1002/adsc.200404023
日期:2004.6
from the reaction of [Cp*(MeCN)3Ru][PF6] with allylic halides were identified as intermediate catalytic species. An X-ray structure determination of the complex [Cp*(MeCHCHCH2)(MeCN)RuBr][PF6] disclosed an (endo-trans-MeCHCHCH2) allylic ligand. The structural information obtained from the study of Cp*(allyl)Ru(IV) complexes indicated that electronic effects at the coordinated allylic ligand likely account
chlorides by carbon nucleophiles and phenols, respectively. After generation of diaminocarbene species upon deprotonation by tBuOK, their association with [Cp*Ru(MeCN)3]PF6 induces a very high regioselectivity in favor of the branched isomers when cinnamyl derivatives are used as starting substrates. They also provide good regioselectivities for the allylation of phenols by unsymmetrical aliphatic allylic
Regio- and Enantioselective Iridium-Catalyzed Intermolecular Allylic Etherification of Achiral Allylic Carbonates with Phenoxides
作者:Fernando López、Toshimichi Ohmura、John F. Hartwig
DOI:10.1021/ja029790y
日期:2003.3.1
An enantioselective and regioselective iridium-catalyzed allylic etherification is described. The reaction of sodium and lithium aryloxides with achiral (E)-cinnamyl and terminal aliphatic allylic electrophiles in the presence of 2 mol % of an iridium-phosphoramidite complex provides chiral allylic aryl ethers in high yields and excellent levels of regio- and enantioselectivity. Lithium aryloxides