Metal-Free Transfer Hydrogenation Catalysis by B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>
作者:Jeffrey M. Farrell、Zachariah M. Heiden、Douglas W. Stephan
DOI:10.1021/om2005832
日期:2011.9.12
The activation of amines by B(C6F5)3 is shown to effect the catalytic racemization of a chiral amine. Extending this strategy to a bimolecular process, catalytic transfer hydrogenation of imines, enamines, and N-heterocycles is demonstrated using iPr2NH as the source of hydrogen and a catalytic amount of the Lewis acid B(C6F5)3.
B(C 6 F 5)3对胺的活化显示出可催化手性胺的消旋化。使用i Pr 2 NH作为氢源和催化量的路易斯酸B(C 6 F 5)3,证明了将该策略扩展为双分子过程,亚胺,烯胺和N-杂环的催化转移氢化。
Enantiopure bisphosphine ligands with appended crown ether groups as regulation sites for Rh-mediated hydrogenations
efficient preparation of a set of enantiopure bisphosphine ligands, whose backbone incorporates an array of diverse crown ethers as distalregulation sites via well-defined supramolecular interactions to tune the catalytic properties of the bisphosphine groups. These new ligands enabled very good catalytic activity in rhodium-mediatedasymmetric hydrogenations at low catalyst loadings, while the enantioselectivity
[Retracted] Enantioselective Rh- or Ir-catalyzed Directed C(sp<sup>3</sup>)–H Borylation with Phosphoramidite Chiral Ligands
作者:Ronald L. Reyes、Tomoya Harada、Tohru Taniguchi、Kenji Monde、Tomohiro Iwai、Masaya Sawamura
DOI:10.1246/cl.170853
日期:2017.12.5
Enantioselective heteroatom-directed C(sp3)–H borylation reactions of 2-aminopyridines and 2-alkylpyridines with Rh- and Ir catalytic systems using commercially available chiral monophosphine ligands, respectively, were developed. This methodology provides an innovative example of a homogeneous catalytic system for C(sp3)–H borylation, and allows the direct synthesis of optically active alkylboronates
分别使用市售的手性单膦配体开发了 2-氨基吡啶和 2-烷基吡啶与 Rh-和 Ir 催化体系的对映选择性杂原子定向 C(sp3)-H 硼酸化反应。该方法为 C(sp3)-H 硼酸化的均相催化系统提供了一个创新示例,并允许直接合成具有中等对映选择性的光学活性烷基硼酸酯。
Chiral Heteropoly Blues and Controllable Switching of Achiral Polyoxometalate Clusters
Managing the blues: Chiralheteropolyblues of achiralpolyoxometalateclusters were created through an intermolecular interaction with a chiral organic compound. Controllable chiroptical switching of the cluster complexes was possible through reversible photochromism of the polyoxometalates (see picture).
A triazine derivative with two short alkyl chains was covalently grafted onto a disk-like polyoxometalate cluster on both sides, and an amphiphilic polyanionic cluster was obtained. The linear cluster complex showed phase separation in polar and non-polar solutions and self-assembled into spherical, planar, and helicalaggregates in turn with the solution polarity decreasing from the methanol/water