Palladium Catalyzed C-Arylation of Amino Acid Derived Hydantoins
摘要:
Palladium(II) trifluoroacetate (5 mol %) catalyzes the C-arylation of N,N-disubstituted hydantoins by aryl iodides in good yield. The reaction proceeds through base-promoted enolization of the amino acid derived hydantoins, and the resulting 5,5-disubstituted hydantoins may be deprotected at one or both N atoms to yield biologically active structures or alternatively hydrolyzed to the parent a-aryl a-amino acids. The reaction is successful with a variety of parent amino acids and a range of electron-rich and electron-poor aryl iodides.
Simple and scalable electrochemical oxidation of the electron-rich benzene ring followed by intramolecular capture of reactive cation-radical intermediates opens access to spirocyclic morpholines and tetrahydrofurans. The obtained molecules can be readily modified to value-added building blocks.
Palladium Catalyzed C-Arylation of Amino Acid Derived Hydantoins
作者:Fernando Fernández-Nieto、Josep Mas Roselló、Simone Lenoir、Simon Hardy、Jonathan Clayden
DOI:10.1021/acs.orglett.5b01803
日期:2015.8.7
Palladium(II) trifluoroacetate (5 mol %) catalyzes the C-arylation of N,N-disubstituted hydantoins by aryl iodides in good yield. The reaction proceeds through base-promoted enolization of the amino acid derived hydantoins, and the resulting 5,5-disubstituted hydantoins may be deprotected at one or both N atoms to yield biologically active structures or alternatively hydrolyzed to the parent a-aryl a-amino acids. The reaction is successful with a variety of parent amino acids and a range of electron-rich and electron-poor aryl iodides.
Azabicyclic Amino Acids by Stereoselective Dearomatizing Cyclization of the Enolates of <i>N</i>-Nicotinoyl Glycine Derivatives
作者:Gareth Arnott、Jonathan Clayden、Stuart D. Hamilton
DOI:10.1021/ol062126s
日期:2006.11.9
by pyridine N-acylation, enolates of N-nicotinoyl and N-isonicotinoyl glycine and alanine derivativescyclize to yield 6,5-azabicyclic or 6,4-azaspirocyclic lactams. With an N-alpha-methyl-p-methoxybenzyl group the cyclization is diastereoselective; hydrogenation and deprotection yields azabicyclic aminoacids in 94:6 er.