Allenes bearing a nucleophilic group cyclize on treatment with acyltetracarbonyl cobalt complexes in the presence of mild bases. Various nucleophilic groups and cobalt complexes can be used to give highly functionalized pyrrolidines, cyclopentanes and tetrahydrofurans. Disubstituted allenes may be used in the reaction. 1,3-disubstituted allenes give products with high stereoselectivity.
Allene Epoxidation. Highly functionalized tetrahydrofurans and tetrahydropyrans from the oxidative cyclization of allenic alcohols.
作者:Jack K. Crandall、David J. Batal、Feng Lin、Thierry Reix、Gregory S. Nadol、Raymond A. Ng
DOI:10.1016/s0040-4020(01)92232-x
日期:1992.2
The dimethyldioxirane oxidation of various allenic alcohols yields highlyfunctionalizedtetrahydrofuran and tetrahydropyran derivatives via intramolecular nucleophilic addition of the hydroxy group to an intermediate allene diepoxide.
Regio- and Stereoselectivity of the Intramolecular C–H Insertion by Cyclopropylidenes Bearing a Remote Oxido Substituent
作者:Toshiro Harada、Yasunari Yamaura、Akira Oku
DOI:10.1246/bcsj.60.1715
日期:1987.5
(ω-Oxidoalkyl)cyclopropylidenes generated from (2,2-dibromo-1-methylcyclopropyl)-CH2–X–(CH2)n–OH (X=CH2 or O, n=1, 2) by the reaction with methyllithium underwent a regioselective intramolecular insertion into the C–H bond at the δ position to the carbenic carbon. The activation effect of the oxido substituent on the reactivity of C–H bonds is discussed on the basis of (1) the ratio of the insertion products
Rhodium‐Catalyzed Asymmetric Intramolecular Hydroamination of Allenes
作者:Dino Berthold、Arne G. A. Geissler、Sabrina Giofré、Bernhard Breit
DOI:10.1002/anie.201904833
日期:2019.7.15
The rhodium‐catalyzed asymmetric intramolecular hydroamination of sulfonyl amides with terminal allenes is reported. It provides selective access to 5‐ and 6‐membered N‐heterocycles, scaffolds found in a large range of different bioactive compounds. Moreover, gram scale reactions, as well as the application of suitable product transformations to natural products and key intermediates thereof are demonstrated
Pd(0)-Catalyzed Tandem Deprotection/Cyclization of Tetrahydro-β-carbolines on Allenes: Application to the Synthesis of Indolo[2,3-<i>a</i>]quinolizidines
作者:Valerian Gobé、Xavier Guinchard
DOI:10.1021/ol500448j
日期:2014.4.4
The pallado-catalyzed tandemdeprotection/cyclization reaction of enantioenriched N-allyl tetrahydro-β-carbolines on allenes is described. The first step generates in situ a deprotected tetrahydro-β-carboline, which then undergoes a cyclization on the allene function via an intermediate π-allyl Pd(II) derivative. This reaction results in the synthesis of various chiralindolic tetracycles (mainly indolo[2
Cyclisation (formation of derivatives of 2-methylidene-cyclopentanol or cyclohexanone) with inversion of configuration and retention of optical activity is observed during the solvolysis of secondary γ-allenic tosylates.