Synthesis of nonionic reduced-sugar based bola amphiphiles and gemini surfactants with an α,ω-diamino-(oxa)alkyl spacer

Reduced-sugar based gemini surfactants with an α,ω-diamino-(oxa)alkyl spacer exhibit a rich pH-dependent aggregation behavior and are efficient DNA carriers in gene transfection. Herein, we describe an improved synthetic procedure for these amphiphiles. First, a series of novel nonionic bolaform amphiphiles with identical headgroups and α,ω-diamino-(oxa)alkyl spacers were synthesized by reductive aminations involving α,ω-diaminoalkanes and the appropriate sugars or aldehydes. The bolaform compounds were used as starting materials for the synthesis of the corresponding reduced-sugar based gemini surfactants in a reductive alkylation reaction employing a polymer-bound cyanoborohydride. A series of new gemini surfactants have been synthesized and characterized.