Scope and applications of second generation palladium-catalyzed cycloalkenylation. Stereoselective total syntheses of isoiridomyrmecin, isodihydronepetalactone, and α-skytanthine

• Published in: Tetrahedron Vol. 67; no. 51; pp. 9909 - 9921
• Main Authors: Takeda, Kazutaka, Toyota, Masahiro
• Format: Journal Article
• Language: English
• Published: OXFORD Elsevier Ltd 23.12.2011; Elsevier
• Subjects: 3-Azabicyclo[3.3.0]octanes; 3-Azabicyclo[4.3.0]nonanes; Bicyclo[3.2.1]octanes; Chemistry; Chemistry, Organic; Physical Sciences; Science & Technology; Second generation palladium-catalyzed cycloalkenylation; α-Skytanthine; Second generation palladium-catalyzed cycloalkenylation; α-Skytanthine; 3-Azabicyclo[3.3.0]octanes; 3-Azabicyclo[4.3.0]nonanes; Bicyclo[3.2.1]octanes; OXIDATION; alpha-Skytanthine; AZA-CLAISEN REARRANGEMENT; DIETHYL AZODICARBOXYLATE; NATURAL-PRODUCTS; RING-SYSTEM; HOMOALLYL RADICAL REARRANGEMENT; ENANTIOSELECTIVE SYNTHESES; PHOSPHORIC ACID; (+)-ALPHA-SKYTANTHINE; MOLECULAR-OXYGEN
• ISSN: 0040-4020; 1464-5416
• DOI: 10.1016/j.tet.2011.08.078

Functionalized bicyclo[3.2.1]octanes, -oxabicyclo-[4.3.0]nonanes, 3-azabicyclo[3.3.0]octanes, and 3-azabicyclo[4.3.0]nonanes were easily synthesized via a second generation palladium-catalyzed cycloalkenylation. Isoiridomyrmecin and isodihydronepetalactone, both of which feature a 3-oxabicyclo[4.3.0]nonane subunit, were stereoselectively synthesized via a second generation palladium-catalyzed cycloalkenylation as the key step. α-Skytanthine, a typical 3-azabicyclo[4.3.0]nonane alkaloid, was also constructed using the same catalytic cyclization protocol. [Display omitted]