Iron-Catalyzed, Hydrogen-Mediated Reductive Cyclization of 1,6-Enynes and Diynes: Evidence for Bis(imino)pyridine Ligand Participation
作者:Kevin T. Sylvester、Paul J. Chirik
DOI:10.1021/ja902478p
日期:2009.7.1
The bis(imino)pyridine iron dinitrogen complex (((i)Pr)PDI)Fe(N(2))(2) catalyzes the hydrogen-mediated reductivecyclization of enynes and diynes with turnover frequencies comparable to those of established precious metal catalysts. Amino, oxygenated, and carbon-based substrates are readily cyclized to the corresponding hetero- and carbocycles with 5 mol % iron and 4 atm H(2) at 23 degrees C. Stoichiometric
Asymmetric Palladium-Catalyzed Alkene Carboamination Reactions for the Synthesis of Cyclic Sulfamides
作者:Zachary J. Garlets、Kaia R. Parenti、John P. Wolfe
DOI:10.1002/chem.201600887
日期:2016.4.18
The synthesis of cyclic sulfamides by enantioselective Pd‐catalyzed alkene carboamination reactions between N‐allylsulfamides and aryl or alkenyl bromides is described. High levels of asymmetric induction (up to 95:5 e.r.) are achieved using a catalyst composed of [Pd2(dba)3] and (S)‐Siphos‐PE. Deuterium‐labelling studies indicate the reactions proceed through syn‐aminopalladation of the alkene and
Synthesis of Polycyclic Nitrogen Heterocycles via Cascade Pd-Catalyzed Alkene Carboamination/Diels–Alder Reactions
作者:Derick R. White、John P. Wolfe
DOI:10.1021/acs.orglett.5b00896
日期:2015.5.15
Cascade Pd-catalyzed alkenecarboamination/Diels–Alder reactions between bromodienes and amines bearing two pendant alkenes are described. These transformations generate 4 bonds, 3 rings, and 3–5 stereocenters to afford polycyclic nitrogen heterocycles with high diastereoselectivity.
Pd-catalyzed asymmetric carboetherification of γ,δ-alkenyl oximes with (hetero)aryl and alkenyl halides in the presence of a commercially available bisphosphine ligand. The enantioenriched products can be facilely converted to functionalized alcohols with high fidelity of chiral transfer.
Density functional theory calculations shed light on the conformational prerequisites for the [2+2] photocycloaddition. The bicyclic key structures could be readily transformed into γ‐cyclobutane amino acids.