Enantioselective radical cyclizations: a new approach to stereocontrol of cascade reactions.
Stereocontrol in a cascade radical addition-cyclization-trapping reaction was achieved by a new approach, which utilizes a hydroxamate ester moiety as a coordinating chiral Lewis acid tether between two radical acceptors. A remarkable feature of this reaction is the construction of three bonds and tertiary and quaternary stereogenic centers through both inter- and intramolecular carbon-carbon bond-forming processes. The chiral Lewis acid mediated reaction of oxime ethers also proceeded smoothly with good enantio- and diastereoselectivities, indicating the usefulness of the cascade approach for the asymmetric synthesis of various gamma-lactams.
School of Pharmacy, Hyogo University of Health Sciences, Minatojima, Kobe 650-8530, Japan. miyabe@huhs.ac.jp
Hideto
H
Miyabe
Yoshiji
Y
Takemoto
D000577:Amides / Q000737:chemistry; D003500:Cyclization; D005609:Free Radicals / Q000737:chemistry; D006877:Hydroxamic Acids / Q000737:chemistry; D007202:Indicators and Reagents; D008968:Molecular Conformation; D010091:Oximes / Q000737:chemistry; D013237:Stereoisomerism
D000577:Amides; D005609:Free Radicals; D006877:Hydroxamic Acids; D007202:Indicators and Reagents; D010091:Oximes