Nonlinear organic reaction of carbamates as base amplifiers to proliferate aliphatic amines and their application to a novel photoreactive system

摘要

The photogeneration of acidic or basic species provides versatile types of photoreactive materials because these species are capable of catalyzing many organic reactions. In particular, a large number of investigations concerning acid-catalyzed systems have been reported.1 However, only a few articles have mentioned photosensitive materials based on base-catalyzed reactions because of relatively low quantum yields for photobase generation of a photobase generator (PBG), leading to low photosensitivity.2"6 If the concentration of a photogenerated base could be boosted by an autocatalytic process, rates of versatile base-catalyzed reactions such as eliminations, condensations and rearrangements should be enhanced considerably. This idea led us to carry out the molecular design and the synthesis of base precursors which are reasonably called base amplifiers since the generation of base molecules occurs in a manner of geometric progression.7"10 Base proliferation processes can be coupled with subsequent base-catalyzed reactions to give various types of nonlinear chemical transformations. We have focused our attention on combining a base amplifier with PBG because a tiny amount of a photogenerated base should be bred, giving rise to photosensitivity enhancement of photoreactive materials sensitized with PBG (Scheme 1).