Study of the Fluorescent Properties of Partially Hydrogenated 1,1′-Bi-2-naphthol-amine Molecules and Their Use for Enantioselective Fluorescent Recognition
作者:Shanshan Yu、Albert M. DeBerardinis、Mark Turlington、Lin Pu
DOI:10.1021/jo200226k
日期:2011.4.15
The fluorescent properties of a series of H8BINOL-amine compounds are investigated. It is revealed that the intramolecular hydrogen bonds of these compounds contribute I to the shift of the emission of their H8BINOL unit to a much longer wavelength. That is, the emission of H8BINOL is at lambda = 323 nm, but that of the H8BINOL-amino alcohol (S)-5 is at lambda = 390 nm. Binding of (3)-5 with mandelic acid suppresses its intramolecular hydrogen bonding and restores the short wavelength emission of the H8BINOL unit. When (S)-s (1.0 x 10(-4) in CH2Cl2) was treated with (R)-mandelic acid (4.0 x 10(-3)), a large fluorescence enhancement at the short wavelength (lambda(emi) = 330 nm) was observed with I-R/I-0 = 11.7. When (S)-MA was used under the same conditions, the enhancement at the short wavelength emission was much smaller. Thus, a good enantioselective fluorescent response was observed with ef =3.5 [ef: enantioselective fluorescence enhancement ratio = (I-R - I-0)/(I-S - I-0)]. This study demonstrates that the H8BINOL-based molecules are promising as a new class of enantioselective fluorescent sensors.
Facile Synthesis of a Family of H<sub>8</sub>BINOL-Amine Compounds and Catalytic Asymmetric Arylzinc Addition to Aldehydes
作者:Albert M. DeBerardinis、Mark Turlington、Jason Ko、Laura Sole、Lin Pu
DOI:10.1021/jo1000516
日期:2010.5.7
compounds, especially for the challenging ortho-substituted aromatic aldehydes. A H8BINOL-AM with 3,3′-bis-sec-amine substituents, prepared by a multistep method, was also used to catalyze the arylzinc addition to aldehydes, but it showed enantioselectivity lower than that of the compounds with tertiary amine groups. It was found for the first time that an aryl bromide, 2-bromothiophene, could be used