Gold(I)/Gold(III) Catalysis that Merges Oxidative Addition and π‐Alkene Activation
作者:Mathilde Rigoulet、Olivier Thillaye du Boullay、Abderrahmane Amgoune、Didier Bourissou
DOI:10.1002/anie.202006074
日期:2020.9.14
possibility to combine oxidative addition of aryl iodides and π‐activation of alkenes at gold is demonstrated for the first time. The reaction is robust and general (>30 examples including internal alkenes, 5‐, 6‐, and 7‐membered rings). It is regioselective and leads exclusively to trans addition products. The (P,N) gold complex is most efficient with electron‐rich aryl substrates, which are troublesome
(MeDalphos)AuCl络合物通过Au I / Au III催化可有效实现烯烃与芳基碘的杂芳基化反应。首次证明了在金中结合芳基碘化物的氧化加成和烯烃的π-活化的可能性。该反应牢固且通用(> 30个实例,包括内部烯烃,5元,6元和7元环)。它是区域选择性的,专门导致反式加成产物。(P,N)金络合物在富电子芳基底物方面效率最高,这对于其他光氧化还原/氧化方法来说是麻烦的。此外,它还提供了从5外向内向6内向区域选择性的非常不同的转换 内部烯醇的Z和E异构体之间的环化。
Oxidative cyclization of tertiary pentenol derivatives forming 2,5,5-trisubstituted THF rings and the total synthesis of cyclocapitelline
作者:Geoffrey A. Phillips、Cory Palmer、Andrew C. Stevens、Mathew L. Piotrowski、Daryl S.R. Dekruyf、Brian L. Pagenkopf
DOI:10.1016/j.tetlet.2015.09.064
日期:2015.10
The synthesis of 2,5,5-trisubstituted tetrahydrofuran rings was accomplished via the Mukaiyama aerobic oxidativecyclization of tertiary 5-pentenols employing the Co(nmp)2 catalyst. A variety of THFs were formed in moderate to good yield and diastereoselectivity. The method developed herein was successfully applied to an enantioselective total synthesis of cyclocapitelline.
Multi-Metal-Catalyzed Oxidative Radical Alkynylation with Terminal Alkynes: A New Strategy for C(sp<sup>3</sup>)–C(sp) Bond Formation
作者:Shan Tang、Yichang Liu、Xinlong Gao、Pan Wang、Pengfei Huang、Aiwen Lei
DOI:10.1021/jacs.8b02745
日期:2018.5.9
for C(sp3)-C(sp) cross-coupling with terminalalkynes has been developed by using a multi-metal-catalyzed reaction strategy. Alkyl radicals generated from different approaches are able to couple with terminalalkynes by judicious selection of the catalyst combination. This reaction protocol offers an efficient alternative approach for the synthesis of substituted alkynes from terminalalkynes besides
Organocatalytic Trapping of Elusive Carbon Dioxide Based Heterocycles by a Kinetically Controlled Cascade Process
作者:Chang Qiao、Alba Villar‐Yanez、Josefine Sprachmann、Bart Limburg、Carles Bo、Arjan W. Kleij
DOI:10.1002/anie.202007350
日期:2020.10.12
A conceptually novel approach is described for the synthesis of six‐membered cyclic carbonates derived from carbon dioxide. The approach utilizes homoallylic precursors that are converted into five‐membered cyclic carbonates having a β‐positioned alcohol group in one of the ring substituents. The activation of the pendent alcohol group through an N‐heterocyclic base allows equilibration towards a thermodynamically
Easy selective generation of (lithiomethyl)cyclopropane or homoallyllithium by a chlorine–lithium exchange
作者:Isidro M. Pastor、Itziar Peñafiel、Miguel Yus
DOI:10.1016/j.tetlet.2008.09.100
日期:2008.11
The reaction of (chloromethyl)cyclopropane 5 with lithium and a catalytic amount of DTBB (5 mol %) in the presence of different carbonyl compounds [Et2CO, n-Pr2CO, (c-C3H5)2CO, (CH2)5CO, PhCOMe, t-BuCHO, i-PrCHO, PhCHO] as electrophiles in THF at −78 °C leads, after hydrolysis with water, to the corresponding cyclopropyl alcohols 6. However, when the same starting material is lithiated using naphthalene