1423401-48-2

Upstream product

• 1100090-79-6 4-{4-trimethylsilylethynyl-2,6-(bishydroxymethyl)-1-phenoxymethyl}benzaldehyde 
• 3182-95-4 L-Phenylalaninol 
• 106-41-2 4-bromo-phenol 
• 6296-63-5 4-bromo-2,6-bis(hydroxymethyl)phenol 
• 1100090-77-4 C₁₆H₁₅BrO₄ 
• 17585-69-2 L-phenylalanine hydrochloride 

Relevant academic research and scientific papers

Two modes of asymmetric polymerization of phenylacetylenes having an L -amino alcohol residue and two hydroxy groups

Four novel chiral phenylacetylenes having an L-amino alcohol residue and two hydroxymethyl groups were synthesized and polymerized by an achiral catalyst ((nbd)Rh+[η6-(C6H5)B -(C6H5)3]) or a chiral catalytic system ([Rh(nbd)Cl]2/(S)- or (R)-phenylethylamine ((S)- or (R)-PEA)). The two resulting polymers having an L-valinol or L-phenylalaninol residue showed Cotton effects at wavelengths around 430 nm. This observation indicated that they had an excess of one-handed helical backbones. Positive and negative Cotton effects were observed only for the polymers having an L-valinol residue produced by using (R)- and (S)-PEA as a cocatalyst, respectively, although the monomer had the same chirality. Even when the achiral catalyst was used, the two resulting polymers having an L-valinol or L-phenylalaninol residue showed Cotton effects despite the long distance between the chiral groups and the main chain. We have found the first example of a new type of chiral monomer, that is, a chiral phenylacetylene monomer having an L-amino alcohol residue and two hydroxy groups that was suitable for both modes of asymmetric polymerization, that is, the helix-sense-selective polymerization (HSSP) with the chiral catalytic system and the asymmetric-induced polymerization (AIP) with the achiral catalyst. The other two monomers having L-alaninol and L-tyrosinol were found to be unsuitable to neither HSSP nor AIP because of their polymers' low solubility.