A one-pot, three-step strategy for the regioselective semihydrogenation of dienes is described. This procedure uses 9-BBN-H as a temporary protective group for alkenes. Yields range from 55% to 95%, and the reaction is tolerant of a variety of common functional groups. Additionally, the final elimination step of the sequence can be replaced with a peroxide-mediated alkylborane oxidation, generating regioselectively semihydrogenated product alcohols.
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http://dx.doi.org/10.1021/jo200262r | DOI Listing |
J Am Chem Soc
March 2024
Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, Hubei, P. R. China.
The first earth-abundant transition metal Ni-catalyzed highly regio- and enantioselective semihydrogenation of racemic tetrasubstituted allenes via a kinetic resolution process as a challenging task was well established. This protocol furnishes expedient access to a diversity of structurally important enantioenriched tetrasubstituted allenes and chiral allylic molecules with high regio-, enantio-, and /-selectivity. Remarkably, this semihydrogenation proceeded with one carbon-carbon double bond of allenes, which was regioselective complementary to the Rh-catalyzed asymmetric version.
View Article and Find Full Text PDFRSC Adv
February 2024
Department of Chemistry and Biochemistry, University of California 5200 North Lake Road 95343 Merced California USA
The manganese(ii) complex [Mn(PNP)Cl] (PNP = 2,6-bis(diisopropylphosphinomethyl)pyridine) was found to catalyze the stereo- and regioselective hydroboration of terminal alkynes employing HBPin (pinacolborane). In the absence of activators, mixtures of alkynylboronate and -alkenylboronate esters were formed, whereas when NaHBEt was employed as the activator, -alkenylboronate esters were exclusively accessed. Mechanistic studies revealed a tandem C-H borylation/semihydrogenation pathway accounting for the formation of the products.
View Article and Find Full Text PDFJ Am Chem Soc
October 2022
Department of Chemistry, Institute of Molecular Plus, School of Science, Tianjin University, Tianjin 300072, China.
Highly chemo- and regioselective semihydrogenation of alkynes is significant and challenging for the synthesis of functionalized alkenes. Here, a sequential self-template method is used to synthesize amorphous palladium sulfide nanocapsules (PdS ANCs), which enables electrocatalytic semihydrogenation of terminal alkynes in HO with excellent tolerance to easily reducible groups (e.g.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2022
State Key Laboratory of Catalytic Materials and Reaction Engineering, Research Institute of Petroleum Processing, Sinopec, Beijing, 100083, China.
It is challenging to establish single metal atoms with a uniform coordination environment at targeted sites of a zeolite. In this study, single platinum atoms were selectively encaged in the six-membered rings of sodalite (SOD) cages within Y zeolite using a template-guiding strategy. During the in situ synthesis process, template molecules were designed to occupy supercages and thereby force coordinated platinum species into SOD cages.
View Article and Find Full Text PDFJ Am Chem Soc
March 2020
Department of Chemistry, University of Minnesota, Minneapolis, Minnesota 55455-0431, United States.
Bimetallic catalysts of nickel(0) with a trivalent rare-earth ion or Ga(III), NiML (where L is [PrPCHNPh], and M is Sc, Y, La, Lu, or Ga), were investigated for the selective hydrogenation of diphenylacetylene (DPA) to ()-stilbene. Each bimetallic complex features a relatively short Ni-M bond length, ranging from 2.3395(8) Å (Ni-Ga) to 2.
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