作者:Alexander C. Campbell、Maurice S. Maidment、John H. Pick、Donald F. M. Stevenson
DOI:10.1039/p19850001567
日期:——
one of which involves a novel Wittig reaction. For the first time, members of the E-series, including the parent (E)-pulvinone, are reported and the structural elucidation of the geometric isomers is described. A method for quantitatively converting (E)-pulvinones into (Z)-pulvinones is presented, together with a technique for differentiating between the isomers.
Iron‐Catalyzed One‐Step Synthesis of Isothiazolone/1,2‐Selenazolone Derivatives via [3+1+1] Annulation of Cyclopropenones, Anilines, and Elemental Chalcogens
作者:Hongchen Wang、Rulong Yan
DOI:10.1002/adsc.202101175
日期:2022.2.15
Described herein is the one-step synthesis of isothiazolone/1,2-selenazolone derivatives via [3+1+1] cycloaddition of cyclopropenone derivatives, anilines, and elemental chalcogens. The cascade reaction involves the C−S, C−N, and N−S bond formation along with the cleavage of C−C bond. Both anilines and cyclopropenones are tolerated and give the corresponding products in 28–73% yields.
Lanthanide Silylamide-Catalyzed Synthesis of Pyrano[2,3-<i>b</i>]indol-2-ones
作者:Qifa Chen、Yue Teng、Fan Xu
DOI:10.1021/acs.orglett.1c01506
日期:2021.6.18
A lanthanide silylamide-catalyzed tandem reaction of isatins, diethyl phosphite, and 2,3-diarylcyclopropenones has been developed. A series of pyrano[2,3-b]indol-2-ones were synthesized in high yields. The cooperation of the Lewis acidity of the lanthanide center and the Bronsted basicity of the N(SiMe3)2 anion may be the key factor affecting the catalytic activity of lanthanide amides.
已经开发了镧系元素甲硅烷基酰胺催化的靛红、亚磷酸二乙酯和 2,3-二芳基环丙烯酮的串联反应。以高产率合成了一系列吡喃并[2,3 - b ]indol-2-ones。镧系元素中心的路易斯酸度和N(SiMe 3 ) 2阴离子的布朗斯台德碱度的协同作用可能是影响镧系酰胺催化活性的关键因素。
Catalytic Asymmetric (3 + 3) Cycloaddition of Oxyallyl Zwitterions with α-Diazomethylphosphonates
作者:Yan Liu、Xian Peng、Rui She、Xin Zhou、Yungui Peng
DOI:10.1021/acs.orglett.1c02809
日期:2021.9.17
The unique structure of oxyallyls represents a significant challenge for their catalyticasymmetric applications. Herein, an unprecedented chiral imidodiphosphoric acid-catalytic enantioselective (3 + 3) cycloaddition between oxyallyl zwitterions generated in situ from α-haloketones and α-diazomethylphosphonates was developed. Pharmaceutically interesting chiral pyridazine-4(1H)-ones were obtained
A Pd-catalyzed enantioselective C–H carbonylation by desymmetrization was developed with commercially available L-pyroglutamic acid as chiral ligand. Isoquinolinones were successfully obtained with good yields and high enantioselectivities. Mechanistic studies and DFT calculations provided a reasonable reaction pathway.