Harnessing the Polarizability of Conjugated Alkynes toward [2 + 2] Cycloaddition, Alkenylation, and Ring Expansion of Indoles
作者:Tapas R. Pradhan、Hong Won Kim、Jin Kyoon Park
DOI:10.1021/acs.orglett.8b02230
日期:2018.9.7
Reported is the utilization of electronically biased conjugated alkynes in the development of highly diastereo- and regioselective dearomative [2 + 2] cycloadditions, alkenylations, and ring expansions of electron-rich indoles. Regioselective protonations of cross- and linear-conjugated alkynes were found to be crucial for accessing various cyclobutene-fused indoline and alkenylated indole derivatives
据报道,在高度非对映和区域选择性脱芳香性[2 + 2]环加成,烯基化和富电子吲哚的环扩展中,利用电子偏置的共轭炔烃。发现交叉和线性共轭炔的区域选择性质子化对于获得各种环丁烯稠合的二氢吲哚和烯基化的吲哚衍生物至关重要。此外,由炔酮成功合成的[2 + 2]酮加合物的容易的环扩展提供了1 H-苯并[ b ]氮杂骨架。
developed. A variety of eight-membered cyclic ethers with two contiguous tertiary stereocenters were obtained in high yields with excellent stereoselectivities. This reaction not only provides a new strategy for constructing enantioenriched eight-membered cyclic ethers but also demonstrates the practicability of ynones as C4-syntons for the synthesis of chiral medium-membered rings.
Palladium-catalyzed carbonylative coupling of (chloromethyl)arenes with terminal arylalkynes to produce 1,4-diaryl-3-butyn-2-ones
作者:Xiujuan Feng、Jiliang Song、Hesong Liu、Liangguang Wang、Xiaoqiang Yu、Ming Bao
DOI:10.1039/c3ra42972e
日期:——
A convenient and efficient method for the synthesis of 1,4-diaryl-3-butyn-2-ones is described. The carbonylative coupling reactions of (chloromethyl)arenes with terminal arylalkynes proceeded smoothly in the presence of a PdCl2(PPh3)2 catalyst under mild reaction conditions to produce the corresponding 1,4-diaryl-3-butyn-2-ones in satisfactory to excellent yields.
Palladium-catalyzed carbonylative coupling of benzyl chlorides with terminal alkynes to give 1,4-diaryl-3-butyn-2-ones and related furanones
作者:Xiao-Feng Wu、Helfried Neumann、Matthias Beller
DOI:10.1039/c1ob06345f
日期:——
A general palladium-catalyzed carbonylative Sonogashira coupling of benzyl chlorides with terminal acetylenes has been established. Depending on the alkyne 1,4-diaryl-3-butyn-2-ones or substituted furanones are obtained in moderate to good yields. Best catalytic performance is achieved applying a mixed Pd(PPh3)Cl2/P(OPh)3 catalyst system.
A variety of 4,5-dihydrofuro[2,3-b]azocin-6-one derivatives were expediently assembled through Au(I)-catalyzed cyclization and 2-(tert-butyl)-1,1,3,3-tetramethylguanidine (BTMG)-mediated [4+4] annulation reactions of enyne-amides and ynones. The reactions exhibit high efficiency with excellent regio- and diastereoselectivity. A broad spectrum of substrates was utilized. The products with an eight-membered
通过 Au(I) 催化环化和 2-(叔丁基)-1,1,3,3-四甲基胍,方便地组装了多种 4,5-二氢呋喃[2,3- b ]azocin-6-one 衍生物(BTMG)-介导的烯炔酰胺和炔酮的[4+4]环化反应。该反应表现出高效率以及出色的区域和非对映选择性。使用了广泛的底物。具有八元环的产品可能在生物化学和医学科学中有用。此外,产品可以很容易地转化为各种衍生物。