Mechanistic study on benzylic oxidations catalyzed by bismuth(III) salts: X-ray structures of two bismuth–picolinate complexes

Resolvable polymorphism in an intergrowth of two modifications of tris(diethyldithiocarbamato)antimony

Tris(diethyldithiocarbamato-κS)antimony(III), [Sb(C₅H₁₀NS₂)₃], is tentatively presumed to comprise a triclinic and a monoclinic polymorph intergrown into each other. The geometry in the triclinic phase is a ψ-capped octahedron and that in the monoclinic phase is a ψ-pentagonal bipyramid. The study also identifies the polyhedral symbols for a reported pair of polymorphs of another Sb^III coordination compound, as well as for those of published polymorphic modifications of other Bi^III and Pb^II coordination compounds; the symbols in the pair differ in most of these examples. When differentiating related structures of such classes of coordination compounds, lone-pair stereochemistry may be another informative variable, as stereochemical activity is not always apparent from bond distances and angles only.

Main Group Redox Catalysis of Organopnictogens: Vertical Periodic Trends and Emerging Opportunities in Group 15

A growing number of organopnictogen redox catalytic methods have emerged-especially within the past 10 years-that leverage the plentiful reversible two-electron redox chemistry within Group 15. The goal of this Perspective is to provide readers the context to understand the dramatic developments in organopnictogen catalysis over the past decade with an eye toward future development. An exposition of the fundamental differences in the atomic structure and bonding of the pnictogens, and thus the molecular electronic structure of organopnictogen compounds, is presented to establish the backdrop against which organopnictogen redox reactivity-and ultimately catalysis-is framed. A deep appreciation of these underlying periodic principles informs an understanding of the differing modes of organopnictogen redox catalysis and evokes the key challenges to the field moving forward. We close by addressing forward-looking directions likely to animate this area in the years to come. What new catalytic manifolds can be developed through creative catalyst and reaction design that take advantage of the intrinsic redox reactivity of the pnictogens to drive new discoveries in catalysis?

Bi(iii)-catalyzed aminooxygenation of propargyl amidines to synthesize 2-fluoroalkyl imidazole-5-carbaldehydes and their decarbonylations

The first example of main group metal Bi(iii)-catalyzed aminooxygenation of fluorinated propargyl amidines was developed to produce 2-fluoroalkyl imidazole-5-carbaldehydes in moderate to excellent yields, in which phenol played a critical role and could be recovered and recycled. In the presence of KOt-Bu, an unconventional decarbonylation occurred on the 2-fluoroalkyl imidazole-5-carbaldehydes.

MnO2 @Fe3 O4 Magnetic Nanoparticles as Efficient and Recyclable Heterogeneous Catalyst for Benzylic sp3 C-H Oxidation

Herein, we report a highly chemoselective and efficient heterogeneous MnO₂ @Fe₃ O₄ MNP catalyst for the oxidation of benzylic sp³ C-H group of ethers using TBHP as a green oxidant to afford ester derivatives in high yield under batch/continuous flow module. This catalyst was also effective for the benzylic sp³ C-H group of methylene derivatives to furnish the ketone in high yield which can be easily integrated into continuous flow condition for scale up. The catalyst is fully characterized by spectroscopic techniques and it was found that 0.424 % MnO₂ @Fe₃ O₄ catalyzes the reaction; the magnetic nanoparticles of this catalyst could be easily recovered from the reaction mixture. The recovered catalyst was recycled for twelve cycles without any loss of the catalytic activity. The advantages of MnO₂ @Fe₃ O₄ MNP are its catalytic activity, easy preparation, recovery, and recyclability, gram scale synthesis with a TOF of up to 14.93 h^-1 and low metal leaching during the reaction.

Simple soluble Bi(iii) salts as efficient catalysts for the oxidation of alkanes with H2O2

Simple soluble Bi(iii) salts exhibit pronounced catalytic activity in the oxidation of inert alkanes with H₂O₂via a radical mechanism with participation of the HO˙ radicals.

Synthesis and characterisation of bismuth(III) aminoarenesulfonate complexes and their powerful bactericidal activity against Helicobacter pylori

The synthesis and characterisation of nine new tris-substituted bismuth(III) aminoarenesulfonates of the general formula [Bi(O3S-R(N))3] (R(N) = o-aminophenyl 1, m-aminophenyl 2, 6-amino-3-methoxyphenyl 3, p-aminophenyl 4, 2-pyridyl 5, o-aminonaphthyl 6, 5-aminonaphthyl 7, 4-amino-3-hydroxynaphthyl 8 and 5-isoquinolinyl 9) is described. Two synthetic strategies, using Ag2O and [Bi(OtBu)3], were explored and compared. The possibility to access heteroleptic bismuth(III) complexes with the new silver(I) metathesis reaction is demonstrated with the synthesis of the heteroleptic bismuth(III) aminoarenesulfonate complexes [PhBi(O3S-P2)2(dmso)] 10, [Ph2Bi(O3S-P2)]∞ 11 and [PhBi(O3S-P2)2]∞ 12, of which the solid state structures 10 and 12 are presented (2P-SO3(-) = 2-pyridinesulfonate). These complexes offer remarkable in-vitro activity against three standard laboratory strains of Helicobacter pylori (H. pylori) as demonstrated by their exceptionally low minimum inhibitory concentration (MIC) values of 0.049 μg  mL(-1) for the strains 251 and B128, which places most MIC values in the nano-molar region. These results demonstrate the importance of the amino functionality in addition to the sulfonate group on the bactericidal properties against H. pylori.

New trends in bismuth-catalyzed synthetic transformations

This review covers uses of bismuth catalysts since 2005 with a special emphasis on the emerging applications of such catalysts. Low toxicity, low catalytic loading, synergistic effects with other catalysts, and some hydrocompatibility properties confer to bismuth salts major advantages. The expanding activity in the field clearly highlights the growing potential of bismuth catalysts. The article is not a comprehensive review on bismuth catalysis but a selection of its most promising uses in challenging synthetic transformations.

(N,N-Dimethyl-formamide-κO)bis-(3-hy-droxy-picolinato-κN,O)phenyl-bis-muth(III)

The title organometallic complex, [Bi(C₆H₅)(C₆H₄NO₃)₂(C₃H₇NO)], features a Bi^III atom in a distorted pentagonal-pyramidal coordination by two N,O-donating bidentate 3-hy­droxy­picolinate (3-hpic) ligands, one monodentate dimethyl­formamide (dmf) mol­ecule and one phenyl ring. The C atom of the aryl ligand occupies the apical position of the BiCN₂O₃ coordination polyhedron, while the equatorial plane is formed by one O atom of the dmf ligand and two sets of N and O atoms from the chelating 3-hpic ligands. Inter­molecular secondary Bi⋯O [3.485 (3) Å] and O—H⋯O hydrogen-bonding inter­actions connect the complexes into a three-dimensional network. Intramolecular O—H⋯O hydrogen bonds are also observed.