One aspect of the present invention relates to quinine-based and quinidine-based catalysts. In certain embodiments, the quinine-based and quinidine-based catalysts contain a hydroxy group at the 6' position. In certain embodiments, the quinine-based and quinidine-based catalysts contain an O-aryl group or an O-aroyl group at the C9 position. In certain embodiments, the quinine-based and quinidine-based catalysts contain an optionally substituted O-diazene group or an optionally substituted O-ben...