A diastereoselective [4+ 2]-annulation of vinyl carbodiimides with chiral N-alkyl imines has
been developed to access the stereochemically rich polycyclic guanidine cores of the …

Two general methods for the synthesis of 2-imino-5-carboxy-3, 4-dihydropyrimidines were
developed using the three-component Biginelli reaction. The first method utilizes pyrazole …

New unusual polycyclic guanidine alkaloids monanchocidins B–E (2–5) along with
monanchocidin A (1), which we recently described, were isolated from the Far-Eastern …

Guanidine plays an important role in medicinal chemistry, coordination chemistry,
organocatalysis, and biochemistry. 1, 2, 3, 4 The ability of this highly polar and basic …

Sponges are among the earliest lineages of metazoans, with first fossil records dated back
to 890 million years ago. All sponge species present associations with microorganisms to …

Four bicyclic and three pentacyclic guanidine alkaloids (1–7) were isolated from a French
Polynesian Monanchora n. sp. sponge, along with the known alkaloids monalidine A (8) …

Chemical study of the CH2Cl2–MeOH (1: 1) extract from the sponge Monanchora
unguiculata collected in Madagascar highlighted five new compounds, one acyclic …

Covering: July 1999–June 2000. Previous review: 2001, 18, 95. This review covers alkaloids
classified in the plant families Amaryallidaceae and Sceletium. In addition alkaloids …

Catalytic asymmetric desymmetrization reactions are powerful and efficient tools for the
synthesis of chiral molecules.[1] These transformations convert simple achiral substrates into …

Oceans have shown to be a remarkable source of natural products. The biological
properties of many of these compounds have helped to produce great advances in …