5707-62-0Relevant academic research and scientific papers
Complex Polyheterocycles and the Stereochemical Reassignment of Pileamartine A via Aza-Heck Triggered Aryl C-H Functionalization Cascades
Bower, John F.,Caiger, Lewis,García-Cárceles, Javier,Hazelden, Ian R.,Jones, Benjamin T.,Langer, Thomas,Lewis, Richard J.
, p. 15593 - 15598 (2021/10/12)
Structurally complex benzo- and spiro-fused N-polyheterocycles can be accessed via intramolecular Pd(0)-catalyzed alkene 1,2-aminoarylation reactions. The method uses N-(pentafluorobenzoyloxy)carbamates as the initiating motif, and this allows aza-Heck-type alkene amino-palladation in advance of C-H palladation of the aromatic component. The chemistry is showcased in the first total synthesis of the complex alkaloid (+)-pileamartine A, which has resulted in the reassignment of its absolute stereochemistry.
Pd(II)-catalyzed intramolecular amidoarylation of alkenes with molecular oxygen as sole oxidant
Yip, Kai-Tai,Yang, Dan
, p. 2134 - 2137 (2011/06/19)
Stereoselective palladium-catalyzed synthesis of structurally versatile indoline derivatives, using molecular oxygen as the sole oxidant, is described. New C-N and C-C bonds form across an alkene in an intramolecular manner. The C-N bond-forming step proceeds via a syn-amidopalladation pathway. The moderate kinetic isotope effects (intramolecular KIE = 3.56) suggest that electrophilic aromatic substitution occurs in the arylation step.
Ligand effects on dirhodium(II) carbene reactivities. Highly effective switching between competitive carbenoid transformations
Padwa, Albert,Austin, David J.,Price, Alan T.,Semones, Mark A.,Doyle, Michael P.,Protopopova, Marina N.,Winchester, William R.,Tran, Andrea
, p. 8669 - 8680 (2007/10/02)
Carboxylate and carboxamide ligands of dirhodium(II) catalysts control chemoselectivity in competitive metal carbene transformations of diazo compounds. For competitive intramolecular cyclopropanation versus intramolecular aromatic substitution with 1-diazo-3-aryl-5-hexen-2-ones, use of Rh2(OAc)4 results in the products from both transformations in nearly equal amounts, but dirhodium(II) perfluorobutyrate (Rh2(pfb)4) provides only the aromatic substitution product while dirhodium(II) caprolactamate (Rh2(cap)4) gives only the cyclopropanation product. Similar results are obtained from dirhodium(II) catalysts in competitive intramolecular cyclopropanation versus tertiary C-H insertion, aromatic cycloaddition versus C-H insertion, cyclopropanation versus aromatic cycloaddition, and C-H insertion versus aromatic substitution. The order of reactivity for metal carbenes generated from Rh2(pfb)4 is aromatic substitution > tertiary C-H insertion > cyclopropanation ～ aromatic cycloaddition > secondary C-H insertion, and the rate differences between them are as much as 100-fold. For Rh2(cap)4 the order of reactivity is cyclopropanation > tertiary C-H insertion > secondary C-H insertion > aromatic cycloaddition with aromatic substitution not observed as a competing process for the diazo compounds examined. Control of chemoselectivity through charge and/or frontier molecular orbital properties of the intermediate metal carbene has been evaluated. Competitive product formation from dirhodium(II) caprolactamate catalyzed reactions of N-tert-butyl-N-benzyldiazoacetoacetamide is temperature dependent over a narrow 15-deg range. The effect of carbene substituents other than the ligated dirhodium(II) on chemoselectivity is described and discussed.
