Gold‐Catalyzed C(sp
<sup>2</sup>
)−C(sp) Coupling by Alkynylation through Oxidative Addition of Bromoalkynes
作者:Yangyang Yang、Jasmin Schießl、Sirine Zallouz、Verena Göker、Jürgen Gross、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/chem.201902213
日期:2019.7.22
gold(I)‐catalyzed cascade cyclization–alkynylation of allenoates using alkynyl bromide to generate β‐alkynyl‐γ‐butenolides was investigated. Whereas alkynyl iodides afforded significant amounts of the homo‐coupling of two lactone units, alkynyl bromides led to a selective reaction, and a broad functional group tolerance was observed. Under the optimized reaction conditions, it was possible to directly synthesize
Phosphine-catalyzed [4 + 2] annulation of γ-benzyl allenoates: facile synthesis of benzothieno[3,2-<i>b</i>]pyran derivatives
作者:Shanshan Ma、Aimin Yu、Xiangtai Meng
DOI:10.1039/c8ob00004b
日期:——
domino reaction between γ-benzyl allenoates and ethyl (Z)-2-(3-oxobenzo[b]thiophen-2(3H)-ylidene)acetate has been developed, which produces a series of 2H-benzo[4,5]thieno[3,2-b]pyran derivatives in high yields. The substrate scope includes both electron-withdrawing (e.g., halogen) and electron-donating (e.g., methoxy) groups on both the benzothiophene and allenoate moieties. The reaction can also be
已开发出一种有效的三(4-甲氧基苯基)膦催化γ-苄基脲基酸酯与(Z)-2-(3-氧代苯并[ b ]噻吩-2(3H)-亚烷基)乙酸乙酯之间的多米诺反应,其产生一系列高产率的2 H-苯并[4,5]噻吩并[3,2- b ]吡喃衍生物。底物范围包括在苯并噻吩和脲基酸酯部分上的吸电子基团(例如卤素)和供电子基团(例如甲氧基)。该反应也可以以克为单位进行,并且收率很高(例如,占77%)。在该反应中,γ-取代的脲基甲酸酯起着两个碳的合成子的作用,其方式迄今在文献中很少报道。
A Phosphine-Catalyzed Novel Asymmetric [3+2] Cycloaddition of C,N-Cyclic Azomethine Imines with δ-Substituted Allenoates
作者:De Wang、Yu Lei、Yin Wei、Min Shi
DOI:10.1002/chem.201405191
日期:2014.11.17
asymmetric [3+2] cycloadditions of C,N‐cyclic azomethine imines with δ‐substituted allenoates have been developed in the presence of (S)‐Me‐f‐KetalPhos, affording functionalized tetrahydroquinoline frameworks in good yields with high diastereo‐ and good enantioselectivities under mild condition. The substrate scope has been also examined. This is the first time that δ‐substituted allenoates have been
Gold-Catalyzed Intramolecular Oxidative Cross-Coupling of Nonactivated Arenes
作者:Matthew N. Hopkinson、Arnaud Tessier、Andrew Salisbury、Guy T. Giuffredi、Lorraine E. Combettes、Antony D. Gee、Véronique Gouverneur
DOI:10.1002/chem.201000322
日期:2010.4.26
An (Au)some coupling! Gold‐catalyzed cascade CO cyclizations of benzyl‐substituted allenoate esters followed by intramolecular oxidative CC cross‐coupling involving aryl CH functionalization were performed with Selectfluor as the oxidant (see scheme). This operationally simple and mild procedure benefits from complete axis‐to‐center chirality transfer and allows for the preparation of surprisingly
Catalyst-Free Synthesis of Novel Dimeric Tetrahydroisoquinoline Derivatives through [2+2+2] Annulation
作者:Hai-Lei Cui、Si Liu、Lu Jiang
DOI:10.1002/ejoc.201900873
日期:2019.8.15
A simple, straightforward and atom economic catalyst‐free [2+2+2] annulation of dihydroisoquinolines and allenoates has been developed, delivering a diverse range of noveldimeric tetrahydroisoquinoline derivatives (37–87 %) from readily available materials.