Synthesis of Group 4 Metal Complexes Stabilized by an Amine-Bridged Bis(phenolato) Ligand and Their Catalytic Behavior in Intermolecular Hydroamination Reactions
bis(phenolato) ligand, have been synthesized and characterized. Although 1 and 2 were inactive in catalyzing intermolecularhydroamination reactions, cationic complexes generated in situ from treatment of 1 and 2 with borate [Ph3C][B(C6F5)4], respectively, were found to be highly active. In general, excellent yields (up to >99%) and 100% regioselectivity for a broad range of terminalalkynes and anilines
Pentacoordinate zirconium complexes 5 and 7 stabilized by amine-bridged bis(phenolato) ligands are more active than hexacoordinate complexes 1–4 in catalyzing intermolecular hydroamination reactions.
A Highly Enantioselective Lewis Basic Organocatalyst for Reduction of <i>N</i>-Aryl Imines with Unprecedented Substrate Spectrum
作者:Zhouyu Wang、Xiaoxia Ye、Siyu Wei、Pengcheng Wu、Anjiang Zhang、Jian Sun
DOI:10.1021/ol060112g
日期:2006.3.2
L-Pipecolinic acid derived formamides have been developed as highly efficient and enantioselective Lewis basic organocatalysts for the reduction of N-aryl imines with trichlorosilane. Catalyst 4b afforded high isolated yields (up to 98%) and enantioselectivities (up to 96%) under mild conditions with an unprecedented substrate spectrum.
BAr<sup>F</sup><sub>3</sub>-Catalyzed Imine Hydroboration with Pinacolborane Not Requiring the Assistance of an Additional Lewis Base
作者:Qin Yin、Yashar Soltani、Rebecca L. Melen、Martin Oestreich
DOI:10.1021/acs.organomet.7b00381
日期:2017.7.10
The rarely used boron Lewis acid tris[3,5-bis(trifluoromethyl)phenyl]borane (BArF3) is found to be an excellent catalyst for metal-free hydroboration of imines. In the presence of 1.0 mol % of BArF3, several ketimines and aldimines undergo hydroboration with pinacolborane (HBpin) at room temperature without the aid of an external Lewis base. BArF3 is more reactive than other Lewis acidic boranes, including
发现很少使用的硼路易斯酸三[3,5-双(三氟甲基)苯基]硼烷(BAr F 3)是无金属亚胺加氢硼化的极佳催化剂。在1.0mol%的BAr F 3的存在下,几种酮亚胺和醛亚胺在室温下与频哪醇硼烷(HBpin)进行硼氢化反应,而无需外部路易斯碱的帮助。BAr F 3比其他路易斯酸性硼烷,包括经常使用的三(五氟苯基)硼烷(B(C 6 F 5)3),具有更高的反应性。B(C 6 F 5)3中六个氟原子邻位赋予硼中心的空间位阻占这个。机械控制实验表明常规的路易斯酸催化涉及亚胺活化和从HBpin转移氢化物。
Hydrogenation and Transfer Hydrogenation Promoted by Tethered Ru−S Complexes: From Cooperative Dihydrogen Activation to Hydride Abstraction/Proton Release from Dihydrogen Surrogates
well as with a representative Hantzsch ester dihydrogen surrogate, are reported. Both processes are catalyzed by tethered Ru−S complexes but differ in the activation mode of the dihydrogen source: cooperative activation of the H−H bond at the Ru−S bond leads to the corresponding Ru−H complex and protonation of the sulfur atom, whereas the same cationic Ru−S catalyst abstracts a hydride from a donor‐substituted