title: DDQ-Promoted Benzylic/Allylic sp(3) C-H Activation for the Stereoselective Intramolecular C-N Bond Formation: Applications to the Total Synthesis of (-)-Codonopsinine, (+)-5-epi-Codonopsinine, (+)-Radicamine B, and (-)-Codonopsinol.
abstract: This is the first report on an intramolecular C-N bond formation of an amide-tethered benzylic/allylic system using DDQ under neutral conditions which has been successfully applied to the total synthesis of naturally occurring pyrolidine alkaloids. The key steps for the synthesis of corresponding precursors involve Julia-Kociensky olefination/cross-metathesis and dihydroxylation reactions, and this methodology is also extended to the ω-unsaturated N-sulfanilamide to furnish piperidines.
authors.affiliation: Organic and Biomolecular Chemistry Division, CSIR-Indian Institute of Chemical Technology , Tarnaka, Hyderabad, 500007 Telangana, India.
authors.forename: Macha
authors.initials: M
authors.lastname: Lingamurthy
authors.affiliation: Organic and Biomolecular Chemistry Division, CSIR-Indian Institute of Chemical Technology , Tarnaka, Hyderabad, 500007 Telangana, India.
authors.forename: Yerri
authors.initials: Y
authors.lastname: Jagadeesh
authors.affiliation: Organic and Biomolecular Chemistry Division, CSIR-Indian Institute of Chemical Technology , Tarnaka, Hyderabad, 500007 Telangana, India.
authors.forename: Katakam
authors.initials: K
authors.lastname: Ramakrishna
authors.affiliation: Organic and Biomolecular Chemistry Division, CSIR-Indian Institute of Chemical Technology , Tarnaka, Hyderabad, 500007 Telangana, India.
authors.forename: Batchu Venkateswara
authors.initials: BV
authors.lastname: Rao
mesh_terms: D015394:Molecular Structure; D010880:Piperidines / Q000737:chemistry*; D011759:Pyrrolidines / Q000138:chemical synthesis* / Q000737:chemistry; D013237:Stereoisomerism
chemical_list: D010880:Piperidines; D011759:Pyrrolidines; C415669:codonopsinine; C000609861:codonopsinol; C450645:radicamine B