Adenine 9- conjugate, preparation

Nucleobases and nucleosides are common motifs for hydrogen-bonded supramolecular arrays. Ng et al. first reported a series of phthalocyanine-nucleobase conjugates [64], The tetra-adenine phthalocyanine 64 was prepared by standard <9-alkylation of zinc(II) tetrahydroxyphthalocyanine with 9-(2-bromoethyl)adenine in the presence of K2CO3. The fluorescence of 64 is quenched substantially upon addition of thymine-substituted 9,10-anthraquinone 65, and the rate is much faster compared with that for the situation when the unsubstituted 9,10-anthraquinone is used as the quencher. These results suggest that 64 forms a supramolecular complex with 65 through the Watson-Crick base-pairing interactions. 

Double bonds conjugated with aldehydes or ketones can selectively be reduced with two different catalytic systems. Both systems use Hantzsch ester derivatives (HEH, 1) as hydride donor, analogous to nicotinamide adenine dinucleotide (NADH, 2), nature s reducing agent (Figure 32.1). These esters were first prepared by Hantzsch in 1882 from ethyl acetoacetate, formaldehyde, and ammonia. The... 

---