Maddess, Matthew L.; Tackett, Miles N.; Watanabe, Hidenori; Brennan, Paul E.; Spilling, Christopher D.; Scott, James S.; Osborn, David P.; Ley, Steven V. Angewandte Chemie - International Edition, 2007, vol. 46, # 4 p. 591 - 597 doi: 10.1002/anie.200604053