Heck reaction synthesis of anthracene and naphthalene derivatives as traps and clean chemical sources of singlet molecular oxygen in biological systems

Abstract

Studies have previously shown that anthracene and naphthalene derivatives serve as compounds for trapping and chemically generating singlet molecular oxygen [O₂(¹Δ_g)], respectively. Simple and efficient synthetic routes to anthracene and naphthalene derivatives are needed, for improved capture and release of O₂(¹Δ_g) in cellular environments. Because of this need, we have synthesized a dihydroxypropyl amide naphthlene endoperoxide as a O₂(¹Δ_g) donor, as well as five anthracene derivatives as O₂(¹Δ_g) acceptor. The anthracene derivatives bear dihydroxypropyl amide, ester, and sulfonate ion end groups connected to 9,10-positions by way of unsaturated (vinyl) and saturated (ethyl) bridging groups. Heck reactions were found to yield these six compounds in easy-to-carry out 3-step reactions in yields of 50–76%. Preliminary results point to the potential of the anthracene compounds to serve as O₂(¹Δ_g) acceptors and would be amenable for future use in biological systems to expand the understanding of O₂(¹Δ_g) in biochemistry.