Studies on enantioselective allylic oxidation of olefins using peresters catalyzed by Cu(i)-complexes of chiral pybox ligands
作者:Sandeep K. Ginotra、Vinod K. Singh
DOI:10.1039/b612423b
日期:——
Enantioselective allylic oxidation of olefins with various peresters, using a catalytic amount of Cu(I)-pybox complex, can be tuned to achieve high asymmetric induction (up to 98% ee) by choosing a unique combination of a ligand and a perester at room temperature. The asymmetric induction in the reaction strongly depends on the nature of the substituents attached to the aryl ring of peresters. The
Copper(II) complexes of pyridine-oxazoline (Pyox) ligands: Coordination chemistry, ligand stability, and catalysis
作者:Andrew J. Hallett、Thomas M. O’Brien、Emma Carter、Benson M. Kariuki、Damien M. Murphy、Benjamin D. Ward
DOI:10.1016/j.ica.2015.10.032
日期:2016.2
The coordinationchemistry of copper(II) complexes bearing pyridine-oxazoline (“Pyox”) ligands has been studied, with an aim of investigating their catalytic ability. Interestingly, the stability of the coordinated ligands has been shown to be much less than previously assumed: hydrolysis of the ligands by fortuitous water gives rise to 2-pyridine carboxylate formation, which encapsulate the copper
已经研究了带有吡啶-恶唑啉(“ Pyox”)配体的铜(II)配合物的配位化学,旨在研究其催化能力。有趣的是,已证明配位配体的稳定性远低于先前的假设:偶然的水使配体水解会生成2-吡啶羧酸盐,从而将铜包封在二维配位聚合物3中。 [Cu(R-Pyox)(NCMe)2(ClO4)2] R =苄基(Bn)2a,苯基(Ph)2b,异丙基(iPr)2c}的制备,其中的苄基衍生物已通过CW EPR光谱。配合物[Cu(Bn-Pyox)(NCMe)2(ClO 4)2]和上述配位聚合物已经在晶体学上进行了表征。
Azaarene cis-dihydrodiol-derived 2,2′-bipyridine ligands for asymmetric allylic oxidation and cyclopropanation
作者:Derek R. Boyd、Narain D. Sharma、Lenuta Sbircea、Deirdre Murphy、Tayeb Belhocine、John F. Malone、Stuart L. James、Christopher C. R. Allen、John T. G. Hamilton
DOI:10.1039/b814678k
日期:——
Biphenyl dioxygenase-catalysed cis-dihydroxylation of 2-chloroquinoline, 2-chloro-3-methylquinoline and 2-chloro-6-phenylpyridine substrates yielded the corresponding enantiopure cis-dihydrodiols; enantiopure 2,2â²-bipyridines, synthesised in four steps from 2-chloroquinoline, proved to be efficient chiral ligands in catalytic asymmetric allylic oxidation and cyclopropanation reactions of alkenes.
Catalytic enantioselective rearrangement of meso-epoxides mediated by chiral lithium amides in the presence of excess cross-linked polymer-bound lithium amides
作者:Atsushi Seki、Masatoshi Asami
DOI:10.1016/s0040-4020(02)00371-x
日期:2002.6
Insoluble polymer-bound achiral lithium dialkylamides were prepared from the corresponding cross-linked polymer-bound amines and butyllithium. The polymer-bound achiral reagent was applied to a catalytic enantioselective rearrangement of meso-epoxides as an in situ regenerating agent of a chiral lithiumamide. The efficiency of the catalytic system was improved, and chiral allylic alcohol derivatives
Enantiospecific Synthesis and Allylation of All-Carbon-Substituted α-Chiral Allylic Stannanes
作者:Eric S. Schmidtmann、Martin Oestreich
DOI:10.1002/anie.200901384
日期:2009.6.8
Once difficult to obtain, the title compounds can be prepared in virtually enantiomerically pure form with a bis(triorganostannyl) zinc reagent (see scheme). Subsequent diastereoselective thermal (left) and Lewis acid promoted reactions (right) illustrate the synthetic potential of these compounds.