Development of Enantioselective Palladium‐Catalyzed Alkene Carboalkoxylation Reactions for the Synthesis of Tetrahydrofurans
作者:Brett A. Hopkins、Zachary J. Garlets、John P. Wolfe
DOI:10.1002/anie.201506884
日期:2015.11.2
The Pd‐catalyzed coupling of γ‐hydroxyalkenes with aryl bromides affords enantiomerically enriched 2‐(arylmethyl)tetrahydrofuran derivatives in good yield and up to 96:4 e.r. This transformation was achieved through the development of a new TADDOL/2‐arylcyclohexanol‐derived chiral phosphite ligand. The transformations are effective with an array of different aryl bromides, and can be used for the preparation
dihydropyrrole-functionalized phenanthridines were efficiently synthesized by the metal-free, radical cascade cyclization reaction of 2-isocyanobiphenyls with γ,δ-unsaturated oxime esters. The C–N/C–C/C–C bonds were formed via the oil bath method in a one-pot procedure with broad substrate applicability. The radical process was supported by kinetic isotope effect studies and radical inhibition studies.
Synthesis of Borylated Carbocycles by [2 + 2]-Cycloadditions and Photo-Ene Reactions
作者:Jarett M. Posz、Neetu Sharma、Paige A. Royalty、Yanyao Liu、Christophe Salome、Thomas C. Fessard、M. Kevin Brown
DOI:10.1021/jacs.4c01557
日期:2024.4.10
agrochemicals and pharmaceuticals. Here, we present the synthesis of borylated bicyclo[2.1.1]hexanes via crossed [2 + 2]-cycloaddition. Due to the presence of the C–B bond, a variety of structures can be easily prepared that are not accessible by other methods. Moreover, a rare photo-ene reaction is also disclosed, allowing for the diastereoselective synthesis of trisubstituted borylated cyclopentanes.
Palladium catalyzed cyclizations of oximeesters with 1,1-disubstituted alkenes: synthesis of α,α-disubstituted dihydropyrroles and studies towards an asymmetric protocol
作者:Adele Faulkner、James S. Scott、John F. Bower
DOI:10.1039/c2cc38944d
日期:——
efficient Pd-catalyzed cyclizations of oxime esters with 1,1-disubstituted alkenes as the basis of a general entry to alpha,alpha-disubstituted pyrrolidine derivatives. We also demonstrate that catalytic asymmetric variants of this chemistry are feasible by employing a suitable chiral ligand.
Stereo- and regioselectivity of cyclization reactions in conformationally restricted epoxy ketones: evaluation of C- versus O-alkylation process
作者:Paolo Crotti、Fabrizio Badalassi、Valeria Di Bussolo、Lucilla Favero、Mauro Pineschi
DOI:10.1016/s0040-4020(01)00817-1
日期:2001.10
The intramolecular addition reaction of metal enolates of ketones to oxiranes has been applied to a series of epoxy ketones derivedfrom cyclohexene oxide. γ-Hydroxy ketones (γ-HKs, C-alkylation products) or hydroxy enol ethers (HEEs, O-alkylation products) are obtained, depending on the nature of the cyclic transition state in each case involved and the application of the Fürst–Plattner rule. The