Palladium Catalyzed 1,8-Conjugate Addition to Heptafulvene <i>via</i> Bis-π-allyl Palladium Complexes
作者:Sholly Clair George、Sreeja Thulasi、S. Anas、K. V. Radhakrishnan、Yoshinori Yamamoto
DOI:10.1021/ol202137m
日期:2011.10.7
palladium catalyzed 1,8-conjugate addition of heptafulvene, an antiaromatic conjugated 8π-electronsystem, is discussed. The method is utilized for the concise synthesis of bis-functionalized cycloheptatriene (CHT) derivatives. This is the first report on the palladium catalyzed bisfunctionalization of a cyclic cross conjugated system.
Oda,M. et al., Journal of the Chemical Society, Section D: Chemical Communications, 1969, p. 739
作者:Oda,M. et al.
DOI:——
日期:——
[8+2] vs [4+2] Cycloadditions of Cyclohexadienamines to Tropone and Heptafulvenes—Mechanisms and Selectivities
作者:Xiangyang Chen、Mathias Kirk Thøgersen、Limin Yang、Rune F. Lauridsen、Xiao-Song Xue、Karl Anker Jørgensen、K. N. Houk
DOI:10.1021/jacs.0c10966
日期:2021.1.20
[4+2] cycloaddition pathways, including chemo-, regio-, and stereoselectivities of these higher-order cycloadditions. The protonated cinchona alkaloid primary amine catalyst reacts with 2-cyclohexenone to form a linear dienamine intermediate that subsequently undergoes a stepwise [8+2] or [4+2] cycloaddition. Both tropone and the different heptafulvenes initially form [8+2] cycloadducts. The final product
stereocontrolled [8+2] and [6+4] cycloadditions have been largely neglected for the past 50 years. Here we demonstrate a cross-dienamine activation of 2-cyclopentenone and the unprecedented endocyclic linear-dienamine activation of 2-cyclohexenones and 2-cycloheptenones. These dienamine intermediates undergo aminocatalytic stereoselective [8+2], [6+4] and formal [4+2] cycloadditions with various heptafulvenes