Efficient guanylation of N,N-difunctionalized polyamines at the secondary amino functions

Treatment of N^α,N^ω-ditritylated linear and aromatic polyamines and of polyamine conjugates of the alkaloid kukoamine A (KukA) type with N,N′-bis(tert-butoxycarbonyl)thiourea in the presence of Mukaiyama’s reagent produced high yields of derivatives guanylated at the secondary amino functions.