Bleaching chemistry of amine boranes with lignin model compounds

Amine boranes can be used efficiently to bleach a spruce-fir high-yield pul p. This paper aims to understand the bleaching chemistry of boranamines wit h lignin model compounds, as well as understand the effect of boranamine tr eatment on light-induced colour reversion. It is shown that the reaction is selective, and the yields are very high. Amine boranes react rapidly and s electively with quinones, then with aromatic aldehydes, and finally with ar omatic ketones. Amine boranes are sensitive to the electron density on the carbonyl group. Reductive bleaching with borane-tert-butylamine complex (TB AB) is complementary to oxidative bleaching using hydrogen peroxide. Chemic al reduction of some beta -O-4 lignin model compounds reduces or inhibits l ight-induced colour reversion.