Metal free highly efficient C-N bond formation through 1,6-addition: synthesis and photophysical studies of diaryl methyl amino acid esters (DMAAEs)

A transition-metal free, proficient strategy for the one-pot synthesis of diverse diaryl methyl amino acid esters (DMAAEs) has been established from the easily accessible chiral amino acid esters andpara-quinone methides (QMs) in very good to excellent yields. Interestingly, peptide molecules having multifunctionalities also reacted chemoselectively withp-QMs in very good yield. The photophysical properties such as emission wavelength and fluorescence efficiency of DMAAEs are significantly dependent on the solvent polarity/nature. A confocal Raman spectroscopy study indicates the structural similarities leading to similar photophysical responses of pyrene derivatives.