Asymmetric α-Pentadienylation of Aldehydes with Cyclopropylacetylenes
作者:Min-Song Wu、Zhi-Yong Han、Liu-Zhu Gong
DOI:10.1021/acs.orglett.0c03466
日期:2021.2.5
cyclopropylacetylene and its derivatives as the pentadienylation reagent, an asymmetric regioselective asymmetric α-pentadienylation reaction of aldehydes is developed by cooperative catalysis of a chiral Pd(0) catalyst and a chiral Brønsted acid in the presence of a subschoichmetric amount of an achiral amine. α-Pentadienylated aldehydes are afforded with high yields and enantioselectivities as well as excellent
A novel PdCl2-catalyzed oxidative cycloisomerization of 3-cyclopropylideneprop-2-en-1-ones, providing a facile synthesis of highly strained functionalized 2-alkylidenecyclobutanones via furan-fused cyclobutene intermediates, is reported. An interesting route to 2(3H)-furanones with a spiro-cyclopropane unit from the obtained 2-alkylidenecyclobutanones via a ring-contraction rearrangement reaction is
Gold-Catalyzed Oxidative Ring Expansions and Ring Cleavages of Alkynylcyclopropanes by Intermolecular Reactions Oxidized by Diphenylsulfoxide
作者:Chia-Wen Li、Kamalkishore Pati、Guan-You Lin、Shariar Md. Abu Sohel、Hsiao-Hua Hung、Rai-Shung Liu
DOI:10.1002/anie.201004647
日期:2010.12.17
A golden opportunity: A novel gold‐catalyzed oxidativering‐expansion of unactivated cyclopropylalkynes using Ph2SO has been developed (see scheme). For substrates bearing a donor group at the cyclopropane ring, preliminary results reveal a distinct cleavage of the cyclopropane unit; such a ringcleavage is further applicable to the synthesis of 2H‐pyrans. L=P(tBu)2(o‐biphenyl), Tf=triflate.
Palladium-Catalyzed Allylation of Cyclopropyl Acetylenes with Oxindoles to Construct 1,3-Dienes
作者:Chuan-Jun Lu、Xin Yu、Yu-Ting Chen、Qing-Bao Song、Zhen-Ping Yang、Hong Wang
DOI:10.1002/ejoc.201901536
日期:2020.2.14
A novel palladium‐catalyzed allylic alkylation of oxindoles with cyclopropylacetylenes has been developed. Various 1,3‐diene oxindole framework bearing a quaternary stereocenter at the C3 position were synthesized straightforwardly in good to excellent yields with high regio‐, and stereoselectivities.