Synthesis of trisubstituted alkenes by reductive dehydroxylation of Baylis–Hillman adducts using polymethylhydrosiloxane (PMHS) and catalytic B(C6F5)3
摘要:
B(C6F5)(3) as a catalyst and polymethylhydrosiloxane as a hydride source have been employed for the reductive dehydroxylation of Baylis-Hillman adducts wherein the hydride adds in an S(N)2' manner onto the unactivated allyl alcohol moiety with concomitant elimination of the hydroxy group along with double bond migration. The products formed were found to be E in the case of ester adducts and Z in the case of nitrile adducts. (c) 2006 Elsevier Ltd. All rights reserved.
Divergent Amine-Catalyzed [4 + 2] Annulation of Morita–Baylis–Hillman Allylic Acetates with Electron-Deficient Alkenes
作者:Silong Xu、Rongshun Chen、Zifeng Qin、Guiping Wu、Zhengjie He
DOI:10.1021/ol2032569
日期:2012.2.17
+ 2] annulation of Morita–Baylis–Hillman allylic acetates 2 with electron-deficientalkenes or diazenes has been developed for efficient syntheses of highly functionalized cyclohexenes, tetrahydropyridazines, and important spirocycles. This reaction unveils a new reactivity pattern of the intensely studied allyliccompounds 2 acting as a C4 synthon in Lewis base catalyzed annulationreactions and also
Palladium-catalyzed intramolecular carbonyl allylation via Claisen rearrangement
作者:Yoshiro Masuyama、Yumiko Nimura、Yasuhiko Kurusu
DOI:10.1016/s0040-4039(00)79019-8
日期:1992.10
Palladium-catalyzed intramolecular carbonyl allylation with SnCl2 by 5-substituted 4-methylene-5-(2-tetrahydropranyloxy)pentanals, prepared by Claisen rearrangement of 2-[1-(2-tetrahydropyranyloxy)alkyl]allylvinylethers, occurred radioselectively at ambienttemperature in DMI/H2O to give 2-substituted 3-methylenecyclopentanols in good yields.
通过2- [1-(2-(4-四氢吡喃氧基)烷基]烯丙基乙烯基醚的克莱森重排制备的5-取代的4-亚甲基-5-(2-四氢戊氧基)戊醛与SnCl 2进行钯催化的分子内羰基烯丙基化反应,于在DMI / H 2 O中的室温下以良好的产率得到2-取代的3-亚甲基环戊醇。
Synthesis of substituted butenolides by the ring closing metathesis of two electron deficient olefins: a general route to the natural products of paraconic acids class
electron-withdrawing groups undergo RCM using the second generation Grubbs’ catalyst in the presence of a Lewis acid resulting in diverse butenolides in high isolated yields. This methodology provides a generalroute to the natural products of paraconic acids class, exemplified by a total synthesis of (±)-phaseolinic acid.
The asymmetric synthesis of α-methylene-γ-butyrolactones via a tandem allylboration/lactonization approach was achieved using a chiral N,N′-dioxide/AlIII complex. The kinetic resolution of the allylboration intermediate via asymmetric lactonization was found to be a key aspect responsible for the success of this transformation. Stereodivergent syntheses and total syntheses of eupomatilones 2, 5 and
使用手性N , N ' -二氧化物/Al III络合物,通过串联烯丙基硼化/内酯化方法实现了 α-亚甲基-γ-丁内酯的不对称合成。发现烯丙基硼化中间体通过不对称内酯化的动力学拆分是该转化成功的关键因素。对Eupomatilones 2、5和6的立体发散合成和全合成证明了其合成实用性。
A New and Efficient Method for the Isomerization of Secondary Functional Allylic Alcohols into their Primary Isomers