Selective Protection of the Primary Amine Functions of Linear Tetraamines Using the Trityl Group

Ethyl 6-Hydroxyfulvene-1-Carboxylate: A Reagent Discriminating Primary Amines from Secondary Amines

A highly chemo-selective reaction was observed when ethyl 6-hydroxyfulvene-1-carboxylate 1 was treated with different nucleophiles such as primary amines, secondary amines, alcohols, and thiols. Among them, only primary amines are reactive toward 1 to afford the condensation products 3, which exhibit good stability under both weakly acidic and basic conditions. The condensation process proved to be reversible between different primary amines. On the basis of this observation, the chemical selectivity of typical primary aromatic amines was evaluated quantitatively by determining equilibrium constants of the condensation reactions with aniline as a reference. Moreover, the primary amines of 3 can be readily released upon treatment with aqueous ammonia, making 6-hydroxyfulvene-1-carboxylate 1 a promising protecting reagent for primary amines.

Xylylated dimers of putrescine and polyamines: influence of the polyamine backbone on spermidine transport inhibition

Dimeric norspermidine and spermidine derivatives are strong competitive inhibitors of polyamine transport. A xylyl tether was used for the dimerization of various triamines and spermine via a secondary amino group, and of putrescine via an ether or an amino group. Dimerization of putrescine moieties potentiates their ability to compete against spermidine transport to a much greater extent than for triamine dimers.