Double Catalytic Enantioselective Alkylation: Total Synthesis of (-)-Cyanthiwigin F

palladium - double alkylation - P,N-ligands

Significance

Double-catalytic transformations are efficient and interesting routes to construct highly complex and functionalized compounds rapidly. There are a number of examples of double-catalytic enantioselective reactions to date (see Reviews below). This report utilizes this unique approach to construct a key precursor to what is arguably the greatest challenge in the synthesis of this natural product.

Reviews

S. Masamune, W. Choy, J. S. Petersen, L. R. Sita Angew. Chem. Int. Ed. 1985, 24, 1-30; O. I. Kolodiazhnyi Tetrahedron 2003, 59, 5953-6018.

Comment

While double-enantioselective catalytic reactions are well known, the authors have cleverly utilized this process to construct two all-carbon quaternary centers in a single step. This rapid approach gave way to the following efficient route to the desired product in a minimum number of steps. The overall transformation is interesting and quite efficient.