Radical Allylation: E-Selective Radical Conjugate Addition–Elimination Reaction from Morita–Baylis–Hillman Adducts
作者:Thierry Lequeux、Cyril Lebargy、Coralie De Schutter、Remi Legay、Emmanuel Pfund
DOI:10.1055/s-0036-1590922
日期:2018.1
Triethylborane-mediated radical allylation was performed from Morita–Baylis–Hillman alcohols with no need of protecting group. The radicalconjugated addition–elimination reaction is highly selective, and trisubstituted E-alkenes were obtained. This reaction opened a new route for the preparation of functionalized α,β-unsaturated ketones.
A FACILE COUPLING REACTION OF VINYL KETONES WITH ALDEHYDES CATALYZED BY RHODIUM(I) HYDRIDE COMPLEX
作者:Susumu Sato、Isamu Matsuda、Yusuke Izumi
DOI:10.1246/cl.1985.1875
日期:1985.12.5
A convenient α-hydroxyalkylation of vinyl ketones is accomplished by the coupling reaction of vinyl ketone and aldehyde, where rhodium(I) enolate derived from HRh(PPh3)4 plays an important role in the carbon–carbon bond forming step.
Remarkably Chemoselective Reduction of Unmodified Baylis-Hillman Adducts by InCl<sub>3</sub>/NaBH<sub>4</sub>: Application to the Stereoselective Synthesis of Trisubstituted Alkenones Including Two Alarm Pheromones
A novel, convenient and solely stereoselective synthesis of trisubstituted E-alkenones has been achieved by InCl 3 /NaBH 4 mediated chemoselective reduction of unmodified Baylis-Hillman adducts derived fromvinylketones and cycloalkenones for the first time. The efficiency of this methodology in the practical synthesis of (s)-(+)-manicone and (S)-(+)-normanicone, two alarm pheromones of Manica ants
overcome this drawback, the effects of pyridinium-based ionic liquids mediated quinuclidine catalytic system for MBH reactions were studied. The method is simple, involving neat and open-flask conditions, and is compatible with a wide range of reagents. We offered general pyridinium-based ionic liquids-mediated quinuclidine catalysis mechanism that is responsible for the observed rate increase. The synthetic
a uracil-copper catalytic system was developed to promote ring-opening allylation of cyclopropanols with allylic alcohols under water-tolerant conditions. A new C–OH bond-breaking model can well resolve the trade-off between the need for acidic activators for C(allyl)–OH bond cleavage and the demand for strong basic conditions for generating homoenolates. Therefore, Morita–Baylis–Hillman alcohols,
受铜与 DNA 和 RNA 的高亲和力的启发,开发了尿嘧啶-铜催化系统,以促进环丙醇与烯丙醇在耐水条件下的开环烯丙基化。一种新的C-OH键断裂模型可以很好地解决C(烯丙基)-OH键断裂所需的酸性活化剂与生成同烯醇盐所需的强碱性条件之间的权衡。因此,Morita-Baylis-Hillman 醇,而不是它们的预活化版本,可以直接掺入与环丙醇的脱水交叉偶联中,产生水作为唯一的副产物。多种功能化的δ 、 ε-不饱和酮以良好到高的收率和高E-选择性获得。