Hydrogen/Halogen Exchange of Phosphines for the Rapid Formation of Cyclopolyphosphines
作者:Adam N. Barrett、Callum R. Woof、Christopher A. Goult、Danila Gasperini、Mary F. Mahon、Ruth L. Webster
DOI:10.1021/acs.inorgchem.1c02734
日期:2021.11.1
The hydrogen/halogen exchange of phosphines has been exploited to establish a truly useable substrate scope and straightforward methodology for the formation of cyclopolyphosphines. Starting from a single dichlorophosphine, a sacrificial proton “donor phosphine” makes the rapid, mild synthesis of cyclopolyphosphines possible: reactions are complete within 10 min at room temperature. Novel (aryl)cyclopentaphosphines
[EN] METHODS FOR PHOSPHINE OXIDE REDUCTION IN CATALYTIC WITTIG REACTIONS<br/>[FR] PROCÉDÉS POUR LA RÉDUCTION D'UN OXYDE DE PHOSPHINE DANS DES RÉACTIONS DE WITTIG CATALYTIQUES
申请人:UNIV DUBLIN CITY
公开号:WO2014140353A1
公开(公告)日:2014-09-18
A method for increasing the rate of phosphine oxide reduction, preferably during a Wittig reaction comprising use of an acid additive is provided. A room temperature catalytic Wittig reaction (CWR) the rate of reduction of the phosphine oxide is increased due to the addition of the acid additive is described. Furthermore, the extension of the CWR to semi-stabilized and non-stabilized ylides has been accomplished by utilization of a masked base and/or ylide-tuning.
method and could easily be purified after isolation. The intermediate formation of the organozinc species is essential, as it prevents the formation of multiple substitution products. Important are also the reaction conditions: the usage of the proper solvent for the respective aromatic precursors and removal of the remaining salts by addition of a dioxane/pentane mixture. Depending on the solvent and
The rhodium-catalyzedasymmetrichydrogenation of various β-dehydroamino acid derivatives to give optically active β-amino acids has been examined. Chiral monodentate 4,5-dihydro-3H-dinaphthophosphepines, which are easily tuned and accessible in a multi-10-g scale, have been used as ligands. The enantioselectivity is largely dependent on the nature of the substituent at the phosphorous atom and on