Chirality- and sequence-selective successive self-sorting via specific homo- and complementary-duplex formations

• Published in: Nature communications Vol. 6; no. 1; p. 7236
• Main Authors: Makiguchi, Wataru, Tanabe, Junki, Yamada, Hidekazu, Iida, Hiroki, Taura, Daisuke, Ousaka, Naoki, Yashima, Eiji
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 08.06.2015; Nature Pub. Group
• Subjects: Acids; Amides; Amidines - chemistry; Carboxylic acids; Carboxylic Acids - chemistry; Chirality; Crystallography, X-Ray; Cyclohexane; Dimerization; Dimers; Hydrogen bonds; Macromolecules; Proton Magnetic Resonance Spectroscopy; Self-recognition; Stereoisomerism; Stereoselectivity
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms8236

Self-recognition and self-discrimination within complex mixtures are of fundamental importance in biological systems, which entirely rely on the preprogrammed monomer sequences and homochirality of biological macromolecules. Here we report artificial chirality- and sequence-selective successive self-sorting of chiral dimeric strands bearing carboxylic acid or amidine groups joined by chiral amide linkers with different sequences through homo- and complementary-duplex formations. A mixture of carboxylic acid dimers linked by racemic-1,2-cyclohexane bis-amides with different amide sequences (NHCO or CONH) self-associate to form homoduplexes in a completely sequence-selective way, the structures of which are different from each other depending on the linker amide sequences. The further addition of an enantiopure amide-linked amidine dimer to a mixture of the racemic carboxylic acid dimers resulted in the formation of a single optically pure complementary duplex with a 100% diastereoselectivity and complete sequence specificity stabilized by the amidinium-carboxylate salt bridges, leading to the perfect chirality- and sequence-selective duplex formation.