Copper complexes of phosphoramidites efficiently catalyzed asymmetricaddition of arylboron reagents to acyclic enones. Importantly, rare 1,4-insertion of arylcopper(I) was identified which led directly to O-bound copper enolates. The new mechanism is fundamentally different from classical oxidative addition/reductive elimination of organocopper(I) on enones.
亚磷酰胺的铜配合物有效地催化芳基硼试剂向无环烯酮的不对称加成。重要的是,鉴定了稀有的芳基铜(I)的 1,4-插入,这直接导致了与 O 结合的铜烯醇化物。新机制与传统的有机铜(I)在烯酮上的氧化加成/还原消除有着根本的不同。
Studies on the Nuclear Magnetic Resonance Spectra of (E)-1-Aryl-3-(2- and 3-thienyl)-2-propenones and Unique Observation of<sup>4</sup>J and<sup>5</sup>J Coupling in Their<sup>1</sup>H-<sup>1</sup>H COSY
作者:In-Sook HanLee、Hyun-Ju Jeon、Chang-Kiu Lee
DOI:10.5012/bkcs.2011.32.2.687
日期:2011.2.20
$^1H$ and $^13}C$ NMR spectra of series of (E)-1-aryl-(2- and 3-thienyl)-2-propenones, that are aldol condensation products between 2- and 3-thiophenecarbaldehydes and m- and p-substituted acetophenones, were examined to make complete assignments of the chemical shifts. Long range couplings, $^4J$ and $^5J$, are observed in the $^1H-^1H$ COSY of both 2- and 3-thienyl compounds, which makes the elucidation of the conformation in solution possible. In contrast, the 2-furyl analogue shows the long range coupling phenomena, but the 3-furyl and phenyl analogues do not show similar phenomena.
Synthesis of symmetrical and unsymmetrical triarylpyrylium ions <i>via</i> an inverse electron demand Diels–Alder reaction
作者:C. T. Fathimath Salfeena、Basavaraja Basavaraja、K. T. Ashitha、V. Praveen Kumar、Sunil Varughese、Cherumuttathu H. Suresh、B. S. Sasidhar
DOI:10.1039/c8cc06444j
日期:——
mediated inverse electron demand Diels–Alder (IEDDA) reaction of chalcones with aryl acetylenes is reported for the synthesis of symmetrical and unsymmetrical 2,4,6-triarylpyrylium ions. The protocol provides an effective one-pot method for the utilization of readily available simple substrates under mild reaction conditions leading to a diverse array of pyrylium ions in moderately good yield.
Solution phase synthesis of a spiro[pyrrolidine-2,3′-oxindole] library via a three component 1,3-dipolar cycloaddition reaction
作者:Demosthenes Fokas、William J. Ryan、David S. Casebier、David L. Coffen
DOI:10.1016/s0040-4039(98)00234-2
日期:1998.4
A combinatorial library of 26,500 spiro[pyrrolidine-2,3′-oxindoles] was prepared in a single-compound format by a facile intermolecular 1,3-dipolarcycloaddition. An azomethine ylide, generated by the decarboxylative condensation of an isatin 1 with an α-amino acid 2, was trapped by a trans-chalcone3 to afford heterocycles of the general structure 4. The regio- and stereochemistry of a representative
Abstract A novel method for the Michael reaction of indoles to α,β‐unsaturatedketones catalyzed by acidic ionic liquid is reported. We obtained the corresponding products in excellent yields in the presence of [hmim]HSO4. Development of this method has resulted in a new protocol for the synthesis of β‐indolylketones.