Distal Alkenyl C–H Functionalization via the Palladium/Norbornene Cooperative Catalysis
作者:Zhao Wu、Nina Fatuzzo、Guangbin Dong
DOI:10.1021/jacs.9b11479
日期:2020.2.12
A distal-selective alkenyl C-H arylation method is reported through a directedpalladium/norbornene (Pd/NBE) cooperative catalysis. The key is to use an appropriate combination of the directing group and the NBE co-catalyst. A range of acyclic and cyclic cis-olefins are suitable substrates, and the reaction is operated under air with excellent site-selectivity. Preliminary mechanistic studies are consistent
报道了一种通过定向钯/降冰片烯(Pd/NBE)协同催化的远端选择性烯基CH芳基化方法。关键是使用导向基团和NBE助催化剂的适当组合。一系列无环和环状顺式烯烃都是合适的底物,反应在空气下进行,具有优异的位点选择性。初步机制研究与所提出的 Pd/NBE 催化 CH 激活而不是 Heck 途径一致。使用 MeI 和溴乙酸甲酯作为亲电子试剂,在远端烷基化方面也取得了初步成功。
Regio- and Diastereocontrol in Carbonyl Allylation by 1-Halobut-2-enes with Tin(II) Halides
diastereoselective. The allylation of benzaldehyde by 1-chlorobut-2-ene in 1,3-dimethylimidazolidin-2-one (DMI) does not occur with tin(II) chloride or bromide but does proceed with tin(II) iodide and exhibits gamma-syn selectivity which is unusual for a Barbier-type carbonylallylation. In the carbonylallylation by 1-chlorobut-2-ene with any tin(II) halide, the addition of tetrabutylammoniumiodide (TBAI) accelerates
Highly Stereoselective Synthesis of<i>Z</i>-Homoallylic Alcohols by Kinetic Resolution of Racemic Secondary Allyl Boronates
作者:Celia A. Incerti-Pradillos、Mikhail A. Kabeshov、Andrei V. Malkov
DOI:10.1002/anie.201300709
日期:2013.5.10
α to Z: Racemic α‐chiral allyl boronates, which are readily synthesized from the respective primary allyl halides, undergo a highly efficient kinetic resolution in a face‐ and Z‐selective allylation of aldehydes catalyzed by the chiral Brønsted acid (R)‐TRIP (see scheme; Epin=tetraethylethylene glycol).
New and Stereoselective Synthesis of 1,4-Disubstituted Buten-4-ols (Homoallylic Alcohol α-Adducts) from the Corresponding γ-Isomers (3,4-Disubstituted Buten-4-ols) via an Acid-Catalyzed Allyl-Transfer Reaction with Aldehydes
from aldehydes via the usual reaction with common allylic metals 1, were converted to the corresponding α-adducts 6 by an acid-catalyzed allyl-transfer reaction. In the allyl-transfer reaction, anti- and syn-γ-adducts 3 gave E- and Z-α-adducts 6, respectively, and the optical purity of the γ-adducts 3 was transferred to the α-adducts 6 with >98%ee. This suggests that the allyl-transfer reaction proceeds
The First Example of Enantioselective Allyl Transfer from a Linear Homoallylic Alcohol to an Aldehyde
作者:Teck-Peng Loh、Chi-Lik Ken Lee、Kui-Thong Tan
DOI:10.1021/ol0263999
日期:2002.8.1
see text] The first example of enantioselective linear homoallylic alcohol transfer reaction was revealed. In all cases, the whole rearrangement is thermodynamically favorable and a steric effect is the drivingforce of this reaction. The preservation of the stereocenter and olefin geometry together with the isolation of gamma-adduct homoallylic alcohols in one isomeric form have warranted the proposed