Steric, Electronic and Conformational Synergistic Effects in the Au(I)-catalyzed alpha-C-H Bond Functionalization of Tertiary Amines
Synthesis of Sulfonyl Halides from Disulfides or Thiols Using Sodium Hypochlorite Pentahydrate (NaOCl·5H2O) Crystals
Synthesis of sulfonyl halides using sodium hypochlorite pentahydrate (NaOCl·5H2O) crystals was studied in detail, considering the reaction rate and yield of the desired product. NaOCl·5H2O reacted with disulfides or thiols in acetic acid to produce sulfonyl chlorides. The yields of the desired sulfonyl chlorides were enhanced when the reaction was performed in (trifluoromethyl)benzene under a CO2 atmosphere. The generation of hypochlorous acid (HOCl) was essential for both reactions. Similarly, sulfonyl bromides were prepared via the reaction of disulfides or thiols with sodium bromide and NaOCl·5H2O crystals in acetic acid owing to the generation of hypobromous acid (HOBr). However, the reaction could not proceed in (trifluoromethyl)benzene under a CO2 atmosphere because bromine was produced instead of HOBr.
Georg Thieme Verlag KG Rüdigerstraße 14, 70469 Stuttgart, Germany
The introduction of remote stereochemistry via successive Type I Anion Relay Chemistry (ARC) coupling of commercially available enantioenriched epoxides has enabled a 20-step total synthesis of (−)-bastimolide A. The streamlined assembly and manipulation of ARC products demonstrates a versatile approach that could be leveraged toward other polyhydroxylated macrolides
A highly convergent total synthesis of (−)-bastimolide A (1), a polyhydroxy antimalarial macrolide, has been achieved via a longest linear sequence of twenty steps from commercially available glycidyl ethers. Type I Anion Relay Chemistry (ARC) coupling tactics enable rapid construction of the molecule's 1,5-polylol backbone. A late-stage B-alkyl Suzuki–Miyaura union and an Evans-modified Mukaiyama macrolactonization generate the forty-membered Z-α,β-unsaturated macrocyclic lactone.
Guest‐Modulated Circularly Polarized Luminescence by Ligand‐to‐Ligand Chirality Transfer in Heteroleptic PdII Coordination Cages
Integrative self-assembly of PdII cations with an enantiopure helicene-based ligand and non-chiral but emissive fluorenone ligands yields a series of Pd2L2L′2 heteroleptic coordination cages, showing circularly polarized luminescence (CPL) from the non-chiral moiety. Modulation of the chiroptical properties is achieved by ligand modification or guest binding, achieving an up to 4-fold enhancement of CPL intensity.
Multicomponent metallo-supramolecular assembly allows the rational combination of different building blocks. Discrete multifunctional hosts with an accessible cavity can be prepared in a non-statistical fashion. We employ our shape-complementary assembly (SCA) method to achieve for the first time integrative self-sorting of heteroleptic PdII cages showing guest-tunable circularly polarized luminescence (CPL). An enantiopure helicene-based ligand (M or P configuration) is coupled with a non-chiral emissive fluorenone-based ligand (A or B) to form a series of Pd2L2L′2 assemblies. The modular strategy allows to impart the chiral information of the helicenes to the overall supramolecular system, resulting in CPL from the non-chiral component. Guest binding results in a 4-fold increase of CPL intensity. The principle offers potential to generate libraries of multifunctional materials with applications in molecular recognition, enantioselective photo-redox catalysis and information processing.
[ASAP] One-Pot Synthesis of 2,3-Disubstituted Indanone Derivatives in Water under Exogenous Ligand-Free and Mild Conditions
Palladium-catalyzed regio- and chemoselective double-alkoxycarbonylation of 1,3-diynes: a computational study
DOI: 10.1039/D2QO00122E, Research Article
DFT calculations have been performed to elucidate the detailed reaction mechanism and the origins of the regio- and chemoselectivities of the palladium-catalyzed double-alkoxycarbonylation of 1,3-diynes.
The content of this RSS Feed (c) The Royal Society of Chemistry
Ni‐Catalyzed Cross‐Coupling of 2‐Iodoglycals and 2‐Iodoribals with Grignard Reagents: A Route to 2‐C‐Glycosides and 2’‐C‐Nucleosides
The importance of O/N-glycosides as biologically active compounds cannot be overstated. This study is focused on the functionalization of glycals and ribals at the C2 position with alkyl, vinyl, aryl, heteroaryl and strained ring substituents. The functionalized glycals and ribals were transformed into 2-C-deoxyglycosides and 2’-C-deoxynucleosides. The application to the synthesis of an analogue of cladribine and clofarabine is described.
The synthesis of 2-C-glycals and 2-C-ribals was achieved in good yields using a nickel-catalyzed cross-coupling between 2-iodoglycals and 2-iodoribal respectively and Grignard reagents. The prepared 2-C-glycals and ribals were then transformed into 2-C-2-deoxyglycosides, 2-C-diglycosides and 2’-C-2’-deoxynucleosides. The developed method was applied to the synthesis of a 2-chloroadenine
2’-deoxyribonucleoside – a structural analogue of cladribine (Mavenclad®, Leustatin®) and clofarabine (Clolar®, Evoltra®), two compounds used in the treatment of relapsing-remitting multiple sclerosis and hairy cell leukemia.