N-alpha-(9-Fluorenylmethyloxycarbonyl)-N-epsilon-(2-trimethylsilyl)ethoxycarbonyl-L-lysine

Teoc, a silicon based amino-protecting group, which can be removed with fluorides as in TBAF. Highly orthogonal to Fmoc and Cbz chemistry; can be used for side specific derivatization, for example for TFA mediated in situ cyclization, which is taking advantage of intermediate aspartamide formation. Towards conditions of Boc chemistry the Teoc group is not sufficiently stable. References: A Tandem In Situ Peptide Cyclization through Trifluoroacetic Acid Cleavage; Koushik Chandra, Tapta Kanchan Roy, Deborah E. Shalev, Abraham Loyter, Chaim Gilon, R. Benny Gerber, and Assaf Friedler; Angew. Chem. Int. Ed. 2014; 53: 9450-9455. DOI: 10.1002/anie.201402789. The ß-(Trimethylsilyl)ethoxycarbonyl amino-protecting group; Tsao, J.-H.; Fell, E.; Hettrich, G.; Carpino, L.A.; Ringsdorf, H. J. Chem. Soc., Chem. Comm. 1978; 358-359. A New Silicon-Based, Fluoride Cleavable Oxycarbonyl Protecting Group Highly Orthogonal to the Boc-, Fmoc- and Cbz-Groups; Martin Golkowski and Thomas Ziegler; Molecules 2011; 16: 4695-4718. Begum Mothia, Antony N. Appleyard, Sjoerd Wadman, and Alethea B. Tabor; Synthesis of Peptides Containing Overlapping Lanthionine Bridges on the Solid Phase: An Analogue of Rings D and E of the Lantibiotic Nisin; Org. Lett. 2011; 13(16): 4216-4219. DOI: 10.1021/ol201548m. P. Sieber; Helv. Chim. Acta 1977; 60: 2711. H. Gerlach; Helv. Chim. Acta 1977; 60: 3039.