Universität zu Köln

Albat, Dominik, Reiher, Martin, Neudoerfl, Joerg-Martin and Schmalz, Hans-Guenther ORCID: 0000-0003-0489-1827 (2021). Improved Synthesis of MediPhos Ligands and Their Use in the Pd-Catalyzed Enantioselective N-Allylation of Glycine Esters. Eur. J. Org. Chem., 2021 (29). S. 4237 - 4243. WEINHEIM: WILEY-V C H VERLAG GMBH. ISSN 1099-0690

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Abstract

A new class of chiral C-2-symmetric diphosphines (MediPhos) was recently shown to give superior results in the Pd-catalyzed asymmetric N-allylation of amino acid esters. We here describe a new, improved protocol for the preparation of such ligands through bidirectional S(N)2-coupling of a tartrate-derived ditosylate with 6-alkyl-2-bromophenols followed by double lithiation/phosphanylation. This method gave access to a series of nine ligands with branched alkyl substituents, which were benchmarked in the enantioselective Pd-catalyzed N-allylation of tert-butyl glycinate with racemic (E)-2,8-dimethylnona-5-en-4-yl methyl carbonate (up to 95 % ee). In addition, the analogous transformation of tert-butyl glycinate with methyl (E)-nona-5-en-4-yl carbonate was optimized. The obtained allylic amines were then used in the stereoselective synthesis of the conformationally restricted proline-derived dipeptide analogs ProM-17 and ProM-21.

Item Type:	Journal Article
Creators:	Creators Email ORCID ORCID Put Code Albat, Dominik UNSPECIFIED UNSPECIFIED UNSPECIFIED Reiher, Martin UNSPECIFIED UNSPECIFIED UNSPECIFIED Neudoerfl, Joerg-Martin UNSPECIFIED UNSPECIFIED UNSPECIFIED Schmalz, Hans-Guenther UNSPECIFIED orcid.org/0000-0003-0489-1827 UNSPECIFIED
URN:	urn:nbn:de:hbz:38-563104
DOI:	10.1002/ejoc.202100748
Journal or Publication Title:	Eur. J. Org. Chem.
Volume:	2021
Number:	29
Page Range:	S. 4237 - 4243
Date:	2021
Publisher:	WILEY-V C H VERLAG GMBH
Place of Publication:	WEINHEIM
ISSN:	1099-0690
Language:	English
Faculty:	Unspecified
Divisions:	Unspecified
Subjects:	no entry
Uncontrolled Keywords:	Keywords Language ALLYLIC SUBSTITUTION; CHIRAL PHOSPHINE; PALLADIUM; AMINATION; NUCLEOPHILES; ALKYLATIONS; DESIGN; COMPLEXES Multiple languages Chemistry, Organic Multiple languages
URI:	http://kups.ub.uni-koeln.de/id/eprint/56310