Merging Halogen-Atom Transfer (XAT) and Copper Catalysis for the Modular Suzuki–Miyaura-Type Cross-Coupling of Alkyl Iodides and Organoborons
作者:Zhenhua Zhang、Bartosz Górski、Daniele Leonori
DOI:10.1021/jacs.1c12649
日期:2022.2.2
Suzuki–Miyaura-type cross-couplings between alkyl iodides and aryl organoborons. This process requires a copper catalyst but, in contrast with previous approaches based on palladium and nickel systems, does not utilizes the metal for the activation of the alkylelectrophile. Instead, this strategy exploits the halogen-atom-transfer ability of α-aminoalkyl radicals to convert secondary alkyl iodides into the
Hydrogen Bonding Phase-Transfer Catalysis with Ionic Reactants: Enantioselective Synthesis of γ-Fluoroamines
作者:Giulia Roagna、David M. H. Ascough、Francesco Ibba、Anna Chiara Vicini、Alberto Fontana、Kirsten E. Christensen、Aldo Peschiulli、Daniel Oehlrich、Antonio Misale、Andrés A. Trabanco、Robert S. Paton、Gabriele Pupo、Véronique Gouverneur
DOI:10.1021/jacs.0c05131
日期:2020.8.19
salts are used as phase-transfer catalysts for fluorination with alkali metal fluorides. We now demonstrate that these organic salts, specifically azetidinium triflates, are suitable substrates for enantioselective ringopening with CsF and a chiral bis-urea catalyst. This process, which highlights the ability of hydrogen bonding phase-transfer catalysts to couple two ionic reactants, affords enantioenriched
铵盐用作碱金属氟化物氟化的相转移催化剂。我们现在证明这些有机盐,特别是氮杂环丁烷三氟甲磺酸盐,是用 CsF 和手性双脲催化剂对映选择性开环的合适底物。该过程突出了氢键相转移催化剂偶联两种离子反应物的能力,以高产率提供了对映体富集的 γ-氟胺。机理研究强调了催化剂在相转移中的作用,并且计算出的过渡态结构解释了对非手性氮杂环丁烷非对映异构体混合物观察到的对映收敛。亲电子试剂中的 N 取代基会影响反应性,但氮的构型对于对映选择性并不重要。
A Rationally Designed Iron(II) Catalyst for C(sp3)−C(sp2) and C(sp3)−C(sp3) Suzuki–Miyaura Cross‐Coupling
A well-defined iron catalyst with high efficiency for Suzuki–Miyaura coupling involving C(sp3) partners is described. In the presence of a lithium amide base, this catalyst enabled, for the first time, C(sp3)−C(sp2) coupling of 1°, 2°, and 3° alkyl halides and (hetero)aryl boronic esters as well as C(sp3)−C(sp3) coupling of 1° and 2° alkyl halides and 1° and 2° alkyl boranes under mild conditions and
The first palladium-catalyzed Hiyama cross-coupling reactions of arylsilanes with 3-iodoazetidine were described. The protocol provides a convenient access to a variety of useful 3-arylazetidines which are of great interest in pharmaceutical laboratories in moderate to good yields (30%-88%). In addition, this strategy has the advantage of easy operation and mild reaction conditions.
Preparation of Aryloxetanes and Arylazetidines by Use of an Alkyl−Aryl Suzuki Coupling
作者:Matthew A. J. Duncton、M. Angels Estiarte、Darlene Tan、Carl Kaub、Donogh J. R. O’Mahony、Russell J. Johnson、Matthew Cox、William T. Edwards、Min Wan、John Kincaid、Michael G. Kelly
DOI:10.1021/ol8011327
日期:2008.8.7
The oxetan-3-yl and azetidin-3-yl substituents have previously been identified as privileged motifs within medicinal chemistry. An efficient approach to installing these two modules into aromatic systems, using a nickel-mediated alkyl-aryl Suzuki coupling, is presented.