Ruthenium-Catalyzed Cyclocarbonylation of Allenyl Alcohols and Amines: Selective Synthesis of Lactones and Lactams
摘要:
Allenyl alcohols such as 4-hydroxybuta-1,2-dienes and 5-hydroxypenta-1,2-dienes having a variety of substituents undergo cyclocarbonylation in the presence of a ruthenium catalyst under mild conditions selectively to give five- and six-membered lactones in a high yield with 100% atom economy. 5-Aminopenta-1,2-dines are also cyclocarbonylated to give gamma-lactams. A possible carbonylation mechanism involving a ruthenium cluster intermediate is proposed on the basis of experimental results.
Highly stereoselective kinetic resolution of α-allenic alcohols: an enzymatic approach
作者:Wenhua Li、Zuming Lin、Long Chen、Xuechao Tian、Yan Wang、Sha-Hua Huang、Ran Hong
DOI:10.1016/j.tetlet.2015.12.098
日期:2016.2
A highly efficient lipase AK-catalyzed direct kinetic resolution of a variety of α-allenic alcohols was developed. With the complementary to previous studies, the current reaction system is effective on a broad range of substituents (R1) at C(1), such as alkyl, aryl, alkenyl, and alkynyl groups. The Jones–Burgess empirical model was modified to interpret the reversed selectivity during the acetylation
Efficient Synthesis of 3-Chloromethyl-2(5<i>H</i>)-furanones and 3-Chloromethyl- 5,6-dihydropyran-2-ones via the PdCl<sub>2</sub>-Catalyzed Chlorocyclocarbonylation of 2,3- or 3,4-Allenols
作者:Xin Cheng、Xuefeng Jiang、Yihua Yu、Shengming Ma
DOI:10.1021/jo8015677
日期:2008.11.21
was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of gamma-lactone 3p. The highly opticallyactive 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available opticallyactive 2,3-allenols. A mechanism for this reaction was proposed.
Allenylic Carbonates in Enantioselective Iridium-Catalyzed Alkylations
作者:David A. Petrone、Mayuko Isomura、Ivan Franzoni、Simon L. Rössler、Erick M. Carreira
DOI:10.1021/jacs.8b01416
日期:2018.4.4
products obtained was highlighted in a variety of stereoselective transition metal-catalyzed difunctionalization reactions. Furthermore, a combination of experimental and theoretical studies provide support for a putative reactionmechanism wherein enantiodetermining C-C coupling occurs via nucleophilic attack on a highly planarized aryl butadienylium π-system that is coordinated to the Ir center in an η2-fashion
Efficient method for propargylation of aldehydes promoted by allenylboron compounds under microwave irradiation
作者:Jucleiton J R Freitas、Queila P S B Freitas、Silvia R C P Andrade、Juliano C R Freitas、Roberta A Oliveira、Paulo H Menezes
DOI:10.3762/bjoc.16.19
日期:——
The propargylation of aldehydes promoted by microwaveirradiation using allenylboron compounds in a chemo- and regioselective way is described. The corresponding products were obtained in short reaction time, high yield and purity without the need of any solvent when allenylboronic acid pinacol ester was used, or using a minimal amount of acetone when potassium allenyltrifluoroborate was used.
Synthesis of Substituted 1,2-Dihydropyridines from Propargyl Vinyl Ethers and Allenic Vinyl Ethers by Gold-Catalyzed Claisen Rearrangement and 6π-Aza-electrocyclization
作者:Hao Wei、Yao Wang、Bin Yue、Peng-Fei Xu
DOI:10.1002/adsc.201000292
日期:2010.10.4
An efficient synthetic method was developed for the construction of substituted 1,2-dihydropyridines by gold-catalyzed tandem reactions. The key intermediates 2,4-dienals were generated from propargyl vinyl ethers or allenic vinyl ethers with gold catalysts. These two reactions involved the process of gold-catalyzed [3,3]-sigmatropic rearrangement/isomerization/amine condensation/6π-aza-electrocyclization