Synthesis of N-Fmoc-(2S,3S,4R)-3,4-dimethylglutamine: An Application of Lanthanide-Catalyzed Transamidation
- 13 July 2005
- journal article
- research article
- Published by American Chemical Society (ACS) in The Journal of Organic Chemistry
- Vol. 70 (16) , 6218-6221
- https://doi.org/10.1021/jo050518r
Abstract
N-Fmoc-(2S,3S,4R)-3,4-dimethylglutamine (6) was synthesized from tert-butyl N-Boc-(2S,3S,4R)-dimethylpyroglutamate (13). This synthesis involved selective deprotection of a Boc group from a lactam nitrogen in the presence of a tert-butyl ester, Fmoc protection of the lactam, and a lanthanide-catalyzed transamidation reaction of the Fmoc-protected lactam, using ammonia and dimethylaluminum chloride. The scope of Lewis acid-catalyzed transamidation of acylated lactams was explored through the variation of lanthanide, lactam, acyl group, amine, and aluminum reagent. The reactivity of various metal triflates was found to vary in the following qualitative order: Yb ∼ Sc > Er ∼ Eu ∼ Sm > Ce ∼ AgI > CuII ∼ Zn. Intriguingly, catalysis was only observed when ammonia was the nitrogen nucleophile; addition of other amidoaluminum complexes to acyl lactams was found to be insensitive to the addition of lanthanides.Keywords
This publication has 12 references indexed in Scilit:
- Enantioselective Formal Hydration of α,β-Unsaturated Imides by Al-Catalyzed Conjugate Addition of Oxime NucleophilesJournal of the American Chemical Society, 2004
- Stereoselective synthesis of (3S,4R)-3,4-dimethyl-(S)-glutamine and the absolute stereochemistry of the natural product from papuamides and callipeltinTetrahedron: Asymmetry, 2001
- Papuamides A−D, HIV-Inhibitory and Cytotoxic Depsipeptides from the Sponges Theonella mirabilis and Theonella swinhoei Collected in Papua New GuineaJournal of the American Chemical Society, 1999
- A facile new method for selective deprotection of N-(tert-butoxycarbonyl)-protected carboxamides with Yb(OTf)3 supported on silica gelTetrahedron Letters, 1998
- Easy Microwave Assisted Deprotection of N-Boc DerivativesSynlett, 1998
- Efficient method for preparation of N-methoxy-N-methyl amides by reaction of lactones or esters with Me2AlClMeONHMe·HClTetrahedron Letters, 1997
- Callipeltin A, an Anti-HIV Cyclic Depsipeptide from the New Caledonian Lithistida Sponge Callipelta sp.Journal of the American Chemical Society, 1996
- Stereospecific synthesis of (2S,4R)-[5,5,5-2H3]leucineJournal of the Chemical Society, Perkin Transactions 1, 1996
- 1-Hydroxy-3-amino-2-piperidone (.delta.-N-hydroxycycloornithine) derivatives: key intermediates for the synthesis of hydroxamate-based siderophoresThe Journal of Organic Chemistry, 1990
- A mild, general method for conversion of esters to amidesTetrahedron Letters, 1977