Acceleration of the Eschenmoser coupling reaction by sonication: efficient synthesis of enaminones by Koduri, N, Hileman, B, Cox, J, Scott, H, Hoang, P, Robbins, A, Bowers, K, Tsebaot, L, Miao, K, Castaneda, M, Coffin, M, Wei, G, Claridge, T, Roberts, K, Hussaini, SR