Palladium-Catalyzed Decarboxylative γ-Olefination of 2,5-Cyclohexadiene-1-carboxylic Acid Derivatives with Vinyl Halides
作者:Chi-Hao Chang、Chih-Ming Chou
DOI:10.1021/acs.orglett.8b00486
日期:2018.4.6
This study explores a Pd-catalyzed decarboxylative Heck-type Csp3–Csp2 coupling reaction of 2,5-cyclohexadiene-1-carboxylic acid derivatives with vinylhalides to provide γ-olefination products. The olefinated 1,3-cyclohexadienes can be further oxidized to produce meta-alkylated stilbene derivatives. Additionally, the conjugated diene products can also undergo a Diels–Alder reaction to produce a bicyclo[2
A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birchreduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C–H olefination followed by rearomatization to deliver ortho-alkylated
An example of proaromatic C(alkenyl)–H olefination is reported. This protocol utilized a freecarboxylicacid as a directing group for C(alkenyl)–H activation of 1,4-cyclohexadiene and coupled with various alkenes. Direct and sequential bisolefinations of proaromatic acids were achieved. The synthetic applicability has been exhibited by [4 + 2] cycloaddition and decarboxylative aromatization of the
Synthesis of Highly Substituted Arenes via Cyclohexadiene–Alkene C–H Cross Coupling and Aromatization
作者:Anup Bhunia、Armido Studer
DOI:10.1021/acscatal.8b00083
日期:2018.2.2
The development of a cross-coupling method for the regioselective β-alkenylation of 2,5-cyclohexadiene carboxylic acid derivatives to form ortho-alkenylarenes through in situ decarboxylation and aromatization is described. The carboxylic acid functionality is used as a traceless directing group for efficient and mild β-alkenylation. The modular sequence comprises a reductive Birch α-alkylation, ionic
作者:Ranee Singh、Anthony N. Reed、Peifei Chu、Conor C.G. Scully、Mei-Kwan Yau、Jacky Y. Suen、Thomas Durek、Robert C. Reid、David P. Fairlie
DOI:10.1016/j.bmcl.2015.10.038
日期:2015.12
Potent ligands for the human complement C3a receptor (C3aR) were developed from the almost inactive tripeptide Leu-Ala-Arg corresponding to the three C-terminal residues of the endogenous peptide agonist C3a. The analogous Leu-Ser-Arg was modified by condensing the serine side chain with the leucine carbonyl with elimination of water to form leucine-oxazole-arginine. Subsequent elaboration with a variety