Ethyl trifluoroacetate: a powerful reagent for differentiating amino groups
作者:Daqiang Xu、Kapa Prasad、Oljan Repic、Thomas J. Blacklock
DOI:10.1016/0040-4039(95)01655-4
日期:1995.10
Selective protection of primary amines in the presence of secondary amines and monofunctionalization of symmetric primary and secondary diamines using ethyl trifluoroacetate is described. Effective differentiation of primary, secondary and tertiary alkyl-substituted primary amines from one another by ethyl trifluoroacetate acylation is also demonstrated. These results are explained on the basis of
A method for using an organic compound to label polynucleotides is described. The method utilizes an organic compound including an oligonucleotide, and electrophilic active site, an active complex, and a phosphate binding site. The oligonucleotide has a sequence that is complimentary to a specific region of a polynucleotide. This facilitates labeling of DNA or RNA at a specific site in its sequence. The active site consists of a stable precursor, and only becomes reactive upon activation. Leaving and protecting functional groups may be attached to the active site in order to facilitate the formation of a stable precursor and subsequent activation. The active complex may be a drug, polypeptide or a reporter molecule such as an isotope or fluorescing compound. The phosphate binding sites may be any functional group capable of forming ionic bonds with phosphate oxygens. Nucleotide labeling using this compound does not interfere with a polynucleotide sequence. The described method for utilizing this compound may be performed in situ. Latent reactivity is utilized to make the reaction chemically specific, alkylating only phosphodiester groups on the polynucleotide. A lactonization reaction traps the trialkylphosphate in a stable form.
An expeditious synthesis of a biscyclam with an aromatic linker
作者:Daqiang Xu、Paul G. Mattner、Kapa Prasad、Oljan Repic、Thomas J. Blacklock
DOI:10.1016/0040-4039(96)01097-0
日期:1996.7
An efficient synthesis of 1 starting from N,N′-bis(3-aminopropyl)ethylenediamine 2 is described. Two salient features of the present work are the selective bis or tris-trifluoracetylation of 2 and a novel bis-macrocyclization of the hexatosyl intermediate 5 using ethylene glycol ditosylate.