914916-65-7Relevant academic research and scientific papers
Efficient silver-mediated acetalation of β,β′- functionalized chlorins
K?pke, Tillmann,Pink, Maren,Zaleski, Jeffrey M.
experimental part, p. 1882 - 1888 (2009/04/08)
We present a novel synthetic strategy to 2,2-dialkoxy-3-oxochlorins [M = 2H, Ni(II), Cu(II)] (i.e., acetaloxochlorins). Reaction of the corresponding 2,3-dioxochlorin with stoichiometric amounts of silver triflate (AgOTf) in the presence of excess alcohol yields the desired acetaloxochlorins within several hours of reflux in up to 90% yield for n-alcohols, and in 25-89% yields for functionalized alcohol substrates. Similar reaction conditions applied to 2-diazo-3-oxochlorins generates the 2,2-dialkoxy-3-oxochlorins (12-60% yields) accompanied by alkoxyporphyrins (10-27% yields). Electronic spectroscopy reveals for the acetaloxochlorins characteristic π-π* absorption features throughout the visible region and their X-ray crystal structures exhibit marked distortion from planarity of the π-conjugated macrocycle due in part to the steric bulk at the periphery. Georg Thieme Verlag Stuttgart.
