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
Chemo-, Regio-, and Enantioselective Rhodium-Catalyzed Allylation of Triazoles with Internal Alkynes and Terminal Allenes
作者:Dino Berthold、Bernhard Breit
DOI:10.1021/acs.orglett.7b03708
日期:2018.2.2
triazole derivatives with internalalkynes and terminalallenes gives access to secondary and tertiary allylic triazoles in very good enantioselectivities. For this process, three new members of the JosPOphos ligand family have been prepared and employed in catalysis. The optimized reaction conditions enable the coupling of triazoles with internalalkynes as well as with allenes, displaying a high tolerance
The invention relates to a process for synthesizing tertiary phosphines by reacting halophosphines with organomagnesium compounds in the presence of copper compounds and optionally of salts.
Die Erfindung betrifft ein Verfahren zur Synthese tertiärer Phosphane durch Umsetzung von Halogenphosphanen mit Organomagnesium-Verbindungen in Gegenwart von Kupferverbindungen und gegebenenfalls von Salzen.
The rhodium-catalyzed asymmetric hydrogenation of different acyclic and cyclic enol carbarnates to give optically active carbarnates has been examined in the presence of chiral monodentate ligands based on a 4,5-dihydro-3H-dinaphthophosphepine motif 4. The enantioselectivity is largely dependent upon the reaction conditions, the nature of substituents on the phosphorus ligand and structure of the enol carbamate. By applying the optimized reaction conditions, enantioselectivities of up to 96% ee have been achieved. (c) 2007 Elsevier Ltd. All rights reserved.