Fluorenylmethyl

Derivatization of primary and secondary amines using 9-fluorenylmethyl chloroformate to form a nonpolar, uv-absorbing derivative has been reported (90,91). Amphetamine and catecholamine were used as probes to evaluate this procedure. The derivatives were well behaved and allowed separation in a short time. 

Fluorenylmethyl esters of A -protected amino acids were prepared using the DCC/ DMAP method (50-89% yield) or by imidazole-catalyzed transesterification of... 

Many carbamates have been used as protective groups. They are arranged in this chapter in order of increasing complexity of stmcture. The most useful compounds do not necessarily have the simplest stmctures, but are /-butyl (BOC), readily cleaved by acidic hydrolysis benzyl (Cbz or Z), cleaved by catalytic hy-drogenolysis 2,4-dichlorobenzyl, stable to the acid-catalyzed hydrolysis of benzyl and /-butyl carbamates 2-(biphenylyl)isopropyl, cleaved more easily than /-butyl carbamate by dilute acetic acid 9-fluorenylmethyl, cleaved by /3-elimination with base isonicotinyl, cleaved by reduction with zinc in acetic acid 1-adamantyl, readily cleaved by trifluoroacetic acid and ally], readily cleaved by Pd-catalyzed isomerisation. 

Methyl Carbamate 5. 9-Fluorenylmethyl Carbamate 8. 2,2,2-Trichloroethyl Carbamate 11. 2-Trimethylsilylethyl Carbamate 16. 1,1-Dimethylpropynyl Carbamate 20. 1-Methyl-1-phenylethyI Carbamate 22. 1-Methyl-l-(4-biphenylyl)ethyl Carbamate 24. 1,1 -Dimethy 1-2-haloethyl Carbamate 26. l,l-Dimethyl-2-cyanoethyl Carbamate 28. r-Butyl Carbamate... 

Fluorenylmethyl, 387 Methoxymethyl, 388 Methylthiomethyl, 389 Tetrahydropyranyl, 390 Tetrahydrofuranyl, 390 Methoxyethoxymethyl, 390 2-(Trimethylsilyl)ethoxymethyl, 391 Benzyloxymethyl, 391 Pivaloyloxymethyl, 391 Phenylacetoxymethyl, 392 Triisopropylsilylmethyl, 392 Cyanomethyl, 392 Acetol, 393 Phenacyl, 393... 

S-p-Methoxybenzyl, 460 S-o- or p-Hydroxy- or Acetoxybenzyl, 462 S-p-Nitrobenzyl, 462 S-2,4,6-Trimethylbenzyl, 462 S-2,4,6-Trimethoxybenzyl, 463 S-4-Picolyl, 463 S-2-Quinolinylmethyl, 464 S-2-Picolyl A/-Oxido, 464 S-9-Anthrylmethyl, 464 S-9-Fluorenylmethyl, 465 S-Xanthenyl, 465 S-Ferroceny I methyl, 466... 

Methyl and Ethyl, 504 9-Fluorenylmethyl, 506 9-(2-Sulfo)fluorenylmethyl, 507 9-(2,7-Dibromo)fluorenylmethyl, 507 17-Tetrabenzo[a,c,gf,/]fluorenylmethyl, 508 2-Chloro-3-indenylmethyl, 508 Benz[f]inden-3-ylmethyl, 508... 

A derivatization with acid chlorides is also possible. Amino acids can be derivatized with 9-fluorenylmethyl chloroformate (FMOC) and separated on a CSP with X-cyclodextrin (ChiraDex gamma ), a cyclic oligosaccharide which consists of eight glucose units. 

Bartok, T., Szalai, G., Lorincz, Zs., Borcsok, G., and Sagi, F., High-speed RP-HPLC/FL analysis of amino acids after automated two-step derivatization with o-phthaldialdehyde/3-mercaptoproprionic acid and 9-fluorenylmethyl chloroformate, /. Liq. Chromatogr., 17, 4391, 1994. 

Byeon et al. [23] described a fluorimetric method for (z>)-penicillamine using 9-fluorenylmethyl pentafluorophenyl carbonate and acetonitrile. Capsules containing penicillamine were extracted with water and then filtered. The solution was incubated at 70 °C for 40 min with borate buffer solution. After cooling, the mixture was extracted with diethyl ether and the fluorescence of the aqueous phase measured at (excitation = 260 nm, emission = 313 nm). The calibration graph was linear for 0.4-5.0 pM of penicillamine with a coefficient of variation of 0.4%. 

A soluble aminomethylated polyethylene glycol and a succinoyl linker were used to support a 9-fluorenylmethyl group for solution-phase glycosylation by the sulfoxide method. With the help of temporary protection by a 6-O-triphenylmethyl ether, the method could be carried out iteratively to form disaccharides (Scheme 4.69) [379],... 

Fluorenyl carbanions, as initiators, 14 258 (+) -1 -(9-Fluorenyl)ethylchloroformate, chiral derivatizing reagent, 6 76t 9-Fluorenylmethyl chloroformate, molecular formula, 6 29It Fluorescamine, chemiluminescence reagent, 5 850... 

Both FMOC and its hydrolysis products have similar absorption and fluorescence spectra to FMOC-amino acids. Excess FMOC remaining after derivatization reacts with water to form 9-fluorenylmethyl alcohol (FMOC-OH), and if this is not removed prior to sample injection, it elutes as a large, broad peak in the vicinity of proline. 

LA Carpino, BJ Cohen, KE Stephens, SY Sadat-Aalaee, J-H Tien, DC Lakgridge. (9-Fluorenylmethyl)oxycarbonyl (Fmoc) amino acid chlorides. Synthesis, characterization, and application to the rapid synthesis of short peptide segments. J Org Chem 51, 3732, 1986... 

LA Carpino, HG Ghao, M Beyermann, M Bienert. (9-Fluorenylmethyl)oxycarbony-lamino acid chlorides in solid-phase peptide synthesis. J Org Chem 56, 2635, 1991. 

---