Micelle‐Mediated Trimerization of Ynals to Orthogonally Substituted 4
H
‐Pyrans in Water: Downstream Rearrangement to Bioactive 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐diene Frameworks
摘要:
AbstractAn efficient trimerization of ynals to diversely substituted 4H‐pyran constructs has been executed in water, under ambient conditions employing micellar catalysis. The method is in agreement with the ideas of green and sustainable chemistry. The locus of the micellar reaction site has been probed through proton NMR studies. A general acid‐mediated downstream rearrangement of the derived 4H‐pyrans to interesting 2,8‐dioxabicyclo[3.3.1]nona‐3,6‐dienes has been observed.
Zinc-Catalyzed Multicomponent Reactions: Easy Access to Furyl-Substituted Cyclopropane and 1,2-Dioxolane Derivatives
作者:Sergio Mata、Jesús González、Rubén Vicente、Luis A. López
DOI:10.1002/ejoc.201600393
日期:2016.5
cyclopropyl-substituted furan derivatives by a zinc-catalyzed three-component coupling of 1,3-dicarbonylic compounds, 2-alkynals and alkenes is reported. A sequence consisting of an initial Knoevenagel condensation, cyclization, and a final cyclopropanation reaction would account for the formation of the final products. In most cases, this multicomponent process proceeds in good yield under mild reaction conditions and
Reactivity of indole-3-alkoxides in the absence of acids: Rapid synthesis of homo-bisindolylmethanes
作者:Bhavani Shankar Chinta、Beeraiah Baire
DOI:10.1016/j.tet.2016.10.067
日期:2016.12
properties of the alkoxides offered the direct and selective construction of bisindolylmethanes and indole-3-carbinols. This process shows very broad scope and represents the reagent (external) free, greener synthesis of structurally divergent bisindolylmethanes.
Copper-Catalyzed A3-Coupling: Synthesis of 3-Amino-1,4-diynes
作者:Yoon-Jeong Choi、Hye-Young Jang
DOI:10.1002/ejoc.201600343
日期:2016.6
the synthesis of 3-amino-1,4-diynes. Although metal-catalyzed A3-coupling reactions have been extensively used to synthesize various propargylamines, the A3-coupling for the synthesis of 3-amino-1,4-diynes has been rarely reported. In this study, various symmetrical 3-amino-1,4-diynes were synthesized by the sequential Cu-catalyzed dealkynylation of propargyl aldehydes followed by A3-coupling. Unsymmetrical
Organocatalytic Asymmetric Synthesis of Propargylamines with Two Adjacent Stereocenters: Mannich-Type Reactions of In Situ Generated C-Alkynyl Imines with β-Keto Esters
作者:Taichi Kano、Taiga Yurino、Keiji Maruoka
DOI:10.1002/anie.201304963
日期:2013.10.25
Side by side: The title reaction is catalyzed by the chiral Brønsted acid (S)‐1, and affords hitherto less accessible chiral propargylamines, having twoadjacentstereocenters, in good to excellent diastereo‐ and enantioselectivities. Boc=tert‐butoxycarbonyl.
Ag-Catalyzed Insertion of Alkynyl Carbenes into C–C Bonds of β-Ketocarbonyls: A Formal C(sp<sup>2</sup>) Insertion
作者:Yongquan Ning、Qingmin Song、Paramasivam Sivaguru、Lizuo Wu、Edward A. Anderson、Xihe Bi
DOI:10.1021/acs.orglett.1c04081
日期:2022.1.21
Here we report a silver-catalyzed alkynyl carbene insertion into β-ketocarbonyls using alkynyl N-nosylhydrazones as alkynyl carbene precursors, which provides access to trisubstituted allenyl ketones. This reaction represents the first example of an alkynyl carbene insertion into a C–C σ bond, affording products homologated with an sp2 carbon center. The products are useful substrates for further transformations