describe a general and efficient protocol for the synthesis of organophosphine compounds from phenols and phosphines (R2PH) via a metal-free C–O bond cleavage and C–P bond formation process. This approach exhibits broad substrate scope and excellent functional group tolerance. The synthetic utilities of this protocol were demonstrated by the synthesis of chiral ligands via the various transformations
Ruthenium-Catalyzed Amination of Secondary Alcohols Using Borrowing Hydrogen Methodology
作者:Kostiantyn O. Marichev、James M. Takacs
DOI:10.1021/acscatal.6b00175
日期:2016.4.1
A new ruthenium complex catalyzes the amination of primary and secondary alcohols and the regioselective mono- and sequential diamination of diols via the borrowing hydrogen pathway. Several variations on new intra- and intermolecular cyclizations of aminoalcohols, diols, and diamines lead to heterocyclic ring systems.
or Et2AlCl, these complexes exhibited considerable to high activity of ethyleneoligomerization. The ligands environments and reaction conditions significantly affect their catalytic activities, while the highest oligomerization activity (up to 1.18 × 106 g · mol−1(Ni) · h−1) was observed for 4d at 20 atm of ethylene. Incorporation of 2–4 equivalents of PPh3 as auxiliary ligands in the 4a–f/MAO catalytic
Synthesis of chiral (phosphinoaryl)oxazolines, a versatile class of ligands for asymmetric catalysis
作者:Guido Koch、Guy C. Lloyd-Jones、Olivier Loiseleur、Andreas Pfaltz、Roger Prétôt、Silvia Schaffner、Patrick Schnider、Peter von Matt
DOI:10.1002/recl.19951140413
日期:——
Enantiomerically pure 2-[2-(diphenylphosphino)aryl]oxazolines are readily prepared from 2-bromobenzonitrile by transmetalation with BuLi, subsequent reaction with chloro-diphenylphosphine and conversion of the resulting phosphinoaryl nitrile to the oxazoline by treatment with a chiral amino alcohol in the presence of ZnCl2. An alternative synthesis is based on the orthometalation of 2-aryloxazolines
Palladium(II) η3-1,3-dimethylallyl complexes 1–4 with chiral and non-chiral substituted 2-[2′-(diphenylphosphino)phenyl]oxazolines as ligands were prepared and characterized by X-ray diffraction studies. The determination of the corresponding solutionstructures were carried out for 1–4 and the complexes 5–6 by 1D and 2D NMR measurements. X-ray and NMR studies equally confirm that the main isomers