Synthesis of 5,5-Disubstituted Butenolides Based on a Pd-Catalyzed γ-Arylation Strategy
作者:Alan M. Hyde、Stephen L. Buchwald
DOI:10.1021/ol9007102
日期:2009.6.18
presence in natural products. Development of the Pd-catalyzed arylation of butenolides with high selectivity for the γ-position allows for a facile construction of quaternary centers. The preparation of a wide variety of γ-aryl butenolides containing a number of functional groups is outlined. An application of this chemistry for a one-pot synthesis of a tricyclic tetrahydroisoquinolinone is demonstrated
Asymmetric Olefin Isomerization of Butenolides via Proton Transfer Catalysis by an Organic Molecule
作者:Yongwei Wu、Ravi P. Singh、Li Deng
DOI:10.1021/ja205674x
日期:2011.8.17
general olefin isomerization was realized via biomimetic protontransfer catalysis with a new chiral organic catalyst. A broad range of mono- and disubstituted β,γ-unsaturated butenolides were transformed into the corresponding chiral α,β-unsaturated butenolides in high enantioselectivity and yield in the presence of as low as 0.5 mol % catalyst. Mechanistic studies have revealed the protonation as the
Synergistic Lewis base and anion-binding catalysis for the enantioselective vinylogous addition of deconjugated butenolides to allenoates
作者:Vikas Kumar、Santanu Mukherjee
DOI:10.1039/c3cc46858e
日期:——
An enantioselective vinylogous umpolung addition of deconjugated butenolides to allenoates has been developed for the first time with the help of synergistic combination of an achiral phosphine and a chiral squaramide, and represents the first example of a catalytic enantioselective Cγ–Cγ bond formation between two different carbonyl partners.
An organocatalyzed method for synthesizing chiral γ,γ-disubstituted γ-butenolides via direct vinylogous aldol reactions of γ-substituted β,γ-butenolides with aldehydes is reported. This reaction is catalyzed by a squaramide–sulfonamide organocatalyst to afford a range of anti-aldol adducts possessing vicinal quaternary and tertiary stereocenters with high to excellent enantioselectivities (reaching
novel Cu(I)-ligand cooperative catalysis. The reaction is enabled by a chiral biphenyl-2-ylphosphine ligand featuring a remote tertiary amino group. Density functional theory studies support the cooperation between the metal center and the ligand basic amino group during the initial soft deprotonation and the key asymmetric γ-protonation. Remarkably, other coinagemetals, that is, Ag and Au, can readily
具有≥96% 对映体过量的 α,β-丁烯内酯是由 β,γ-丁烯内酯通过新型 Cu(I)-配体协同催化合成的。该反应由具有远程叔氨基的手性联苯-2-基膦配体实现。密度泛函理论研究支持金属中心和配体碱性氨基在初始软去质子化和关键不对称γ-质子化过程中的合作。值得注意的是,其他造币金属,即 Ag 和 Au,在这种不对称异构化化学中可以很容易地承担与 Cu 相同的作用。