J Org Chem
Department of Chemistry, College of the Holy Cross, 1 College Sreet, Worcester, Massachusetts 01610, United States.
Published: June 2021
The desymmetrization of ten prochiral diols by phosphoryl transfer with a titanium-BINOLate complex is discussed. The phosphorylation of nine 1,3-propane diols is achieved in yields of 50-98%. Enantiomeric ratios as high as 92:8 are achieved with diols containing a quaternary C-2 center incorporating a protected amine. The chiral ligand, base, solvent, and stoichiometry are evaluated along with a nonlinear effect study to support an active catalyst species that is oligomeric in chiral ligand. The use of pyrophosphates as the phosphorylating agent in the desymmetrization facilitates a user-friendly method for enantioselective phosphorylation with desirable protecting groups (benzyl, -nitrobenzyl) on the phosphate product.
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http://dx.doi.org/10.1021/acs.joc.1c00414 | DOI Listing |
Nat Commun
January 2025
College of Chemistry and Life Science, Advanced Institute of Materials Science, Changchun University of Technology, Changchun, P. R. China.
The enantioselective domino Heck/cross-coupling has emerged as a powerful tool in modern chemical synthesis for decades. Despite significant progress in relative rigid skeleton substrates, the implementation of asymmetric Heck/cross-coupling cascades of highly flexible haloalkene substrates remains a challenging and and long-standing goal. Here we report an efficient asymmetric domino Heck/Tsuji-Trost reaction of highly flexible vinylic halides with 1,3-dienes enabled by palladium catalysis.
View Article and Find Full Text PDFJ Trace Elem Med Biol
January 2025
Center for Global Health Research (CGHR), Saveetha Medical College, Saveetha Institute of Medical and Technical Sciences (SIMATS), Saveetha University, Chennai, India. Electronic address:
[CuL(tmen)] is a sequence of four ternary mononuclear Schiff base copper(II) complexes that are derived from L-valine, suitable 5'-substituted-2'-hydroxyacetophenones (where the substituents are -Cl for L, -Me for L, -OMe for L, and -H for L), and tmen (where tmen-N,N,N',N' tetramethyl ethylenediamine). Without isolating the Schiff base ligand or producing any other intermediate products, all of the complexes were synthesised. These compounds were identified using elemental analysis, molar conductance, UV-Vis, FTIR, EPR, VSM-RT, and CD spectra.
View Article and Find Full Text PDFAcc Chem Res
January 2025
Shenzhen Grubbs Institute and Department of Chemistry, Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis, Guangdong Provincial Key Laboratory of Catalysis, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
ConspectusChiral organosilicon compounds bearing a Si-stereogenic center have attracted increasing attention in various scientific communities and appear to be a topic of high current relevance in modern organic chemistry, given their versatile utility as chiral building blocks, chiral reagents, chiral auxiliaries, and chiral catalysts. Historically, access to these non-natural Si-stereogenic silanes mainly relies on resolution, whereas their asymmetric synthetic methods dramatically lagged compared to their carbon counterparts. Over the past two decades, transition-metal-catalyzed desymmetrization of prochiral organosilanes has emerged as an effective tool for the synthesis of enantioenriched Si-stereogenic silanes.
View Article and Find Full Text PDFOrg Lett
January 2025
Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel.
A novel class of bis-8-aryl-isoquinoline () bis-alkylamine iron complexes, Fe()(OTf) and Fe()(OTf) ( = dipyrrolidinyl or = ,'-dimethylcyclohexyl-diamine), for asymmetric oxidation reactions is reported. The scalable divergent synthesis of 8-aryl-3-formylisoquinolines (), the key intermediates in preparing these ligands, enables precise structural and electronic tuning around the metal center. The enantioselective epoxidation and hydroxy carbonylation of conjugated alkenes, mediated by the Fe() catalyst with HO as the oxidant, demonstrates the potential of these redox Fe[N] catalysts in inducing face selection in oxygen transfer transformations.
View Article and Find Full Text PDFChem Commun (Camb)
January 2025
Department of Organic Synthesis and Process Chemistry, CSIR-Indian Institute of Chemical Technology (CSIR-IICT), Hyderabad 500007, India.
Herein, we have developed a Pd(II)-catalyzed cyclization of prochiral alkyne-tethered malononitriles to access five-membered carbocycles having a nitrile-containing all-carbon quaternary center. The reaction pathway involves a -acetoxypalladation, nitrile group insertions into the carbon-palladium bond and sequential deacetylation followed by -acetylation. Initial studies on asymmetric cyclization were also performed with chiral Pyox ligands.
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