The silyl palladium complexes (dcpe)PdH(SiHtBu2) and (dcpe)Pd(SiHMe2)2 display NMR spectra that vary with temperature. The dynamic NMR behavior is consistent with long-lived sigma-complexes as intermediates. In the case of (dcpe)PdH(SiHtBu2), the intermediate is believed to be a symmetric complex with doubly bridged hydrogen atoms between the silicon and palladium. Dynamic interchange of the two silicon atoms in (dcpe)Pd(SiHMe2)2 is consistent with an intermediate Si-Si sigma-complex.
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http://dx.doi.org/10.1021/ja063344j | DOI Listing |
Org Lett
October 2024
Department of Biochemistry, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, Texas 75390-9038, United States.
We report the stereoselective total synthesis of rhodocoranes I and J in 10 steps and 16.4% overall yield from ()-limonene. The synthesis was accomplished through the convergent assembly of a highly substituted chiral cyclopentanone and a lithiated furanyl silyl ketene acetal.
View Article and Find Full Text PDFAdv Sci (Weinh)
September 2024
Engineering Center of Catalysis and Synthesis for Chiral Molecules, Department of Chemistry, Fudan University Shanghai, Shanghai, 200433, China.
A Pd-catalyzed enantioselective aminosilylation of alkenes via tandem Aza-Heck/silylation reaction under Pd/Sadphos catalysis is disclosed. A wide array of oxime esters and silicon reagents are tolerated, furnishing the chiral pyrrolines bearing one quaternary or two contiguous stereocenters in good yield with high enantioselectivity. Not only terminal alkenes but also tri-substituented internal alkenes successfully participate in the reaction, delivering vicinal stereocenters in complete diastereoselectivity and high enantioselectivity.
View Article and Find Full Text PDFOrg Lett
July 2024
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Henan 473061, China.
A palladium(II)-catalyzed norbornene-mediated remote selective -C-H silylation of primary benzamides was developed for the synthesis of arylsilanes. Such a conversion provides access to a range of arylsilanes with exclusive selectivity using norbornene (NBE) as the -C-H activator. The amide directing group can be detached simultaneously through C-C bond cleavage or undergo a dehydration reaction pathway to form nitriles.
View Article and Find Full Text PDFOrg Lett
February 2024
College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Henan 473061, China.
A palladium/norbornene (NBE)-catalyzed regioselective C-H silylation of free NH-indoles is reported. This protocol uses Pd(OAc) as the catalyst and Cu(OAc) as the oxidant, and the reaction relies on the control of NBE as a switch. The reaction tolerates various functional groups, and a series of silicon-containing indoles were directly synthesized in 30%-94% yields.
View Article and Find Full Text PDFChemistrySelect
May 2023
Department of Chemistry, Kansas State University, Manhattan, Kansas 66506, U.S.A.
Tricyclic pyrone (TP) molecules have shown protection of MC65 neuroblastoma cells death induced by amyloid-β proteins through SβC gene, a decrease of amyloid-β peptide levels, and improvement of motor functions and memory in Alzheimer's disease mouse and rat models. Mechanistic studies suggest TP molecules modulate -methyl--aspartate receptor. A short synthesis of chiral TP analogs was sought using a Pd(0)-catalyzed displacement of TP allylic acetate intermediate with sodium azide or substituted benzylamines.
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