Phosphino-amine (PN) Ligands for Rapid Catalyst Discovery in Ruthenium-Catalyzed Hydrogen-Borrowing Alkylation of Anilines: A Proof of Principle
作者:Lewis Marc Broomfield、Yichen Wu、Eddy Martin、Alexandr Shafir
DOI:10.1002/adsc.201500562
日期:2015.11.16
A general synthetic protocol for the synthesis of simple phosphino-amine (PN) ligands is described with 19 ligands being isolated in good yields. High-throughput ligand screening uncovered the success of two of these ligands for aromatic amine alkylations via ruthenium-catalyzedhydrogen borrowing reactions. The combination of N,N′-bis(diphenylphosphino)-N,N′-dimethylpropylenediamine with a ruthenium(II)
Aluminium complexes of salanol ligands: coordination chemistry and stereoselective lactide polymerization
作者:Rami Hador、Sophia Lipstman、Raffaella Rescigno、Vincenzo Venditto、Moshe Kol
DOI:10.1039/d0cc05957a
日期:——
The tetradentate dianionic ONNO}-type salanol ligands featuring phenolate and alcoholate arms and a chiral-bipyrrolidine core are introduced. The diastereoselectively-formed ONNO}-Al-OBn complexes catalyze the ring-opening polymerization of rac-lactide and meso-lactide by either the dual stereocontrol or the chain-end stereocontrol mechanisms to give PLAs of all possible tacticities.
Zinc Complexes of Bipyrrolidine‐Based Diamine‐Diphenolato and Diamine‐Diolato Ligands: Predetermination of Helical Chirality Around Tetrahedral Centres
作者:Ekaterina Sergeeva、Konstantin Press、Israel Goldberg、Moshe Kol
DOI:10.1002/ejic.201300151
日期:2013.7
conversions. Most complexes were obtained as mononuclear complexes. The least bulky Salan ligand, Lig3, led to an equilibrium between mononuclear and dinuclear complexes in noncoordinating solvents. All ligands were found to wrap around the tetrahedral zinc with very high diastereoselectivities supporting predeterminedchiral induction from the bipyrrolidine core to the helicalligand wrapping. Molecular
Readily Accessible Bulky Iron Catalysts exhibiting Site Selectivity in the Oxidation of Steroidal Substrates
作者:David Font、Mercè Canta、Michela Milan、Olaf Cussó、Xavi Ribas、Robertus J. M. Klein Gebbink、Miquel Costas
DOI:10.1002/anie.201600785
日期:2016.5.4
Bulky iron complexes are described that catalyze the site‐selective oxidation of alkyl C−H bonds with hydrogen peroxide under mild conditions. Steric bulk at the iron center is introduced by appending trialkylsilyl groups at the meta‐position of the pyridines in tetradentate aminopyridine ligands, and this effect translates into high product yields, an enhanced preferential oxidation of secondary over
catalyzes highly enantioselective epoxidation of olefins with H2O2 is described. Improvement of enantiomeric excesses is attained by the use of catalytic amounts of carboxylic acid additives. Electronic effects imposed by the ligand on the iron center are shown to synergistically cooperate with catalytic amounts of carboxylic acids in promoting efficient O-O cleavage and creating highly chemo- and