title: Enantioselective palladium(0)-catalyzed Nazarov-type cyclization.
abstract: A Pd(0)-catalyzed asymmetric Nazarov-type cyclization is described. The optimized ligand for the reaction incorporates a weakly coordinating pyridine ring into a TADDOL-derived phosphoramidite (TADDOL=α,α,α,α-tetraaryl-1,3-dioxolane-4,5-dimethanol). The reaction leads to the formation of cyclopentenones as single diastereoisomers that incorporate two contiguous asymmetric centers, one tertiary and one an all-carbon-atom quaternary stereocenter, in high yield and optical purity. It is noteworthy that the reaction does not require that substrates should be activated by aryl substituents.
authors.affiliation: Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822 (USA).
authors.forename: Kei
authors.initials: K
authors.lastname: Kitamura
authors.affiliation: Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822 (USA).
authors.forename: Naoyuki
authors.initials: N
authors.lastname: Shimada
authors.affiliation: Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822 (USA).
authors.forename: Craig
authors.initials: C
authors.lastname: Stewart
authors.affiliation: Chemistry Department, The University of Texas-Pan American, 1201 West University Drive, Edinburg, TX 78539-2999 (USA).
authors.forename: Abdurrahman C
authors.initials: AC
authors.lastname: Atesin
authors.affiliation: Chemistry Department, The University of Texas-Pan American, 1201 West University Drive, Edinburg, TX 78539-2999 (USA).
authors.forename: Tülay A
authors.initials: TA
authors.lastname: Ateşin
authors.affiliation: Chemistry Department, University of Hawaii at Manoa, 2545 The Mall, Honolulu, HI 96822 (USA). tius@hawaii.edu.|University of Hawaii Cancer Center, 701 Ilalo Street, Honolulu, HI 96813 (USA). tius@hawaii.edu.
authors.forename: Marcus A
authors.initials: MA
authors.lastname: Tius
mesh_terms: D002384:Catalysis; D003500:Cyclization; D003517:Cyclopentanes / Q000138:chemical synthesis* / Q000737:chemistry; D004148:Dioxolanes / Q000737:chemistry*; D000432:Methanol / Q000031:analogs & derivatives* / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*; D013237:Stereoisomerism
chemical_list: D003517:Cyclopentanes; D004148:Dioxolanes; C516101:alpha,alpha,alpha',alpha'-tetraaryl-1,3-dioxolane-4,5-dimethanol; D010165:Palladium; C013905:cyclopentenone; D000432:Methanol
keywords: TADDOLs; asymmetric synthesis; cyclization; enantioselectivity; palladium