Water-soluble SNS cationic palladium(II) complexes and their Suzuki–Miyaura cross-coupling reactions in aqueous medium
- Alphonse Fiebor,
- Richard Tia,
- Banothile C. E. Makhubela and
- Henok H. Kinfe
Beilstein J. Org. Chem. 2018, 14, 1859–1870, doi:10.3762/bjoc.14.160
Graphical Abstract
Figure 1: Examples of reported SCS palladium(II) pincer complexes 1–13.
Figure 2: a) Reported SNS palladium(II) pincer complexes 14–16 as catalysts for Suzuki–Miyaura cross coupling ...
Scheme 1: Synthesis of pincer ligands 19a–d and complexes 17a–d.
Figure 3: Molecular structure of 17d. Selected bond distances (Å) and bond angles (°); S(1)–Pd(1)–Cl(1) 93.27...
Scheme 2: Proposed mechanism of the Suzuki–Miyaura coupling reaction using pincer complex 17d.
Figure 4: Energy profile for the oxidative addition reaction involving 4-bromoanisole and Pd(II) catalyst pre...
Scheme 3: Investigation on the reusability of the catalyst.
Figure 5: Reusability of pincer complex 17d as a catalyst for the Suzuki–Miyaura cross coupling reaction.
Scheme 4: Suzuki–Miyaura coupling reaction catalysed by the SN-bidentate complex 20a.
β-Hydroxy sulfides and their syntheses
- Mokgethwa B. Marakalala,
- Edwin M. Mmutlane and
- Henok H. Kinfe
Beilstein J. Org. Chem. 2018, 14, 1668–1692, doi:10.3762/bjoc.14.143
Graphical Abstract
Figure 1: Some sulfur-containing natural products.
Figure 2: Some natural products incorporating β-hydroxy sulfide moieties.
Figure 3: Some synthetic β-hydroxy sulfides of clinical value.
Scheme 1: Alumina-mediated synthesis of β-hydroxy sulfides, ethers, amines and selenides from epoxides.
Scheme 2: β-Hydroxy sulfide syntheses by ring opening of epoxides under different Lewis and Brønsted acid and...
Scheme 3: n-Bu3P-catalyzed thiolysis of epoxides and aziridines to provide the corresponding β-hydroxy and β-...
Scheme 4: Zinc(II) chloride-mediated thiolysis of epoxides.
Scheme 5: Thiolysis of epoxides and one-pot oxidation to β-hydroxy sulfoxides under microwave irradiation.
Scheme 6: Gallium triflate-catalyzed ring opening of epoxides and one-pot oxidation.
Scheme 7: Thiolysis of epoxides and one-pot oxidation to β-hydroxy sulfoxides using Ga(OTf)3 as a catalyst.
Scheme 8: Ring opening of epoxide using ionic liquids under solvent-free conditions.
Scheme 9: N-Bromosuccinimide-catalyzed ring opening of epoxides.
Scheme 10: LiNTf2-mediated epoxide opening by thiophenol.
Scheme 11: Asymmetric ring-opening of cyclohexene oxide with various thiols catalyzed by zinc L-tartrate.
Scheme 12: Catalytic asymmetric ring opening of symmetrical epoxides with t-BuSH catalyzed by (R)-GaLB (43) wi...
Scheme 13: Asymmetric ring opening of meso-epoxides by p-xylenedithiol catalyzed by a (S,S)-(salen)Cr complex.
Scheme 14: Desymmetrization of meso-epoxide with thiophenol derivatives.
Scheme 15: Enantioselective ring-opening reaction of meso-epoxides with ArSH catalyzed by a C2-symmetric chira...
Scheme 16: Enantioselective ring-opening reaction of stilbene oxides with ArSH catalyzed by a C2-symmetric chi...
Scheme 17: Asymmetric desymmetrization of meso-epoxides using BINOL-based Brønsted acid catalysts.
Scheme 18: Lithium-BINOL-phosphate-catalyzed desymmetrization of meso-epoxides with aromatic thiols.
Scheme 19: Ring-opening reactions of cyclohexene oxide with thiols by using CPs 1-Eu and 2-Tb.
Scheme 20: CBS-oxazaborolidine-catalyzed borane reduction of β-keto sulfides.
Scheme 21: Preparation of β-hydroxy sulfides via connectivity.
Scheme 22: Baker’s yeast-catalyzed reduction of sulfenylated β-ketoesters.
Scheme 23: Sodium-mediated ring opening of epoxides.
Scheme 24: Disulfide bond cleavage-epoxide opening assisted by tetrathiomolybdate.
Scheme 25: Proposed reaction mechanism of disulfide bond cleavage-epoxide opening assisted by tetrathiomolybda...
Scheme 26: Cyclodextrin-catalyzed difunctionalization of alkenes.
Scheme 27: Zinc-catalyzed synthesis of β-hydroxy sulfides from disulfides and alkenes.
Scheme 28: tert-Butyl hydroperoxide-catalyzed hydroxysulfurization of alkenes.
Scheme 29: Proposed mechanism of the radical hydroxysulfurization.
Scheme 30: Rongalite-mediated synthesis of β-hydroxy sulfides from styrenes and disulfides.
Scheme 31: Proposed mechanism of Rongalite-mediated synthesis of β-hydroxy sulfides from styrenes and disulfid...
Scheme 32: Copper(II)-catalyzed synthesis of β-hydroxy sulfides 15e,f from alkenes and basic disulfides.
Scheme 33: CuI-catalyzed acetoxysulfenylation of alkenes.
Scheme 34: CuI-catalyzed acetoxysulfenylation reaction mechanism.
Scheme 35: One-pot oxidative 1,2-acetoxysulfenylation of Baylis–Hillman products.
Scheme 36: Proposed mechanism for the oxidative 1,2-acetoxysulfination of Baylis–Hillman products.
Scheme 37: 1,2-Acetoxysulfenylation of alkenes using DIB/KI.
Scheme 38: Proposed reaction mechanism of the diacetoxyiodobenzene (DIB) and KI-mediated 1,2-acetoxysulfenylat...
Scheme 39: Catalytic asymmetric thiofunctionalization of unactivated alkenes.
Scheme 40: Proposed catalytic cycle for asymmetric sulfenofunctionalization.
Scheme 41: Synthesis of thiosugars using intramolecular thiol-ene reaction.
Scheme 42: Synthesis of leukotriene C-1 by Corey et al.: (a) N-(trifluoroacetyl)glutathione dimethyl ester (3 ...
Scheme 43: Synthesis of pteriatoxins with epoxide thiolysis to attain β-hydroxy sulfides. Reagents: (a) (1) K2...
Scheme 44: Synthesis of peptides containing a β-hydroxy sulfide moiety.
Scheme 45: Synthesis of diltiazem (12) using biocatalytic resolution of an epoxide followed by thiolysis.
Synthesis of 1,2-cis-2-C-branched aryl-C-glucosides via desulfurization of carbohydrate based hemithioacetals
- Henok H. Kinfe,
- Fanuel M. Mebrahtu,
- Mandlenkosi M. Manana,
- Kagiso Madumo and
- Mokela S. Sokamisa
Beilstein J. Org. Chem. 2015, 11, 583–588, doi:10.3762/bjoc.11.64
Graphical Abstract
Scheme 1: (i) CAN, wet silica, KBr, CH2Cl2/CH3CN (1:1), rt, 30 min; (ii) a. NaOAc, Ac2O, 140 °C, 3 h; b. K2CO3...
Figure 1: Single X-ray crystal structure of hemithioacetal 3a.
Scheme 2: Proposed reaction sequence for the synthesis of a mixture of carbaldehydes 5a and 5a’ using Raney n...
Scheme 3: K2CO3 (catalytic amount), MeOH, rt, 30 min.
