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The reactivity of the hydroxo di-n-butyltin trifluoromethanesulfonato dimer complex [n-Bu2Sn(µ-OH)(H2O)(CF3SO3)]2 (1) toward 1,10-phenanthroline (phen) has been investigated, leading to the formation of two novel di-n-butyltin(IV) trifluoromethanesulfonate complexes [n-Bu2Sn(µ-OH)(phen)]2[CF3SO3]2 (5) and [n-Bu2Sn(phen)2][CF3SO3]2 (6), in which the tin atoms are bis-chelated by one and two bidentate phen ligands, respectively. Salts 5 and 6 were characterized by single crystal X-ray diffraction analysis, elemental analysis, mass spectrometry, and infrared spectroscopy as well as 1H, 19F, 13C{1H}, and 119Sn{1H} NMR spectroscopy. Monitoring by 119Sn{1H} NMR spectroscopy in CD3CN solution of the reaction proceeding with successive addition of phen revealed the in situ formation of three organotin(IV) trifluoromethanesulfonate intermediate species. Two of these, namely {[n-Bu2Sn(H2O)]2O·n-Bu2Sn(OH)2}[CF3SO3]2 (2) and [n-Bu2Sn2(OH)(CF3SO3)]2O (4), were already known and could be clearly identified on the basis of their 119Sn{119H} NMR chemical shifts. The composition of the third intermediate, 3, with an unknown chemical shift value, was investigated. A possible structure, especially suggested by electrospray-ionization mass spectrometry, is proposed as [{n-Bu2Sn(phen)(CF3SO3)}2(µ-CF3SO3)][CF3SO3]. Furthermore, from a mixture of 1 and phen in equimolar ratio, in dichloromethane solvent and at –20 °C, temperature-sensitive crystals of a new hydrated di-n-butyltin cation, [n-Bu2Sn(phen)(OH)(H2O)][CF3SO3] (7), were isolated. Crystals of the organic salt 1,10-phenanthrolinium trifluoromethanesulfonate (phenHOTf) were also obtained from the filtrate of the mother-liquor. The reactivity of 1 toward 2,9-dimethyl-1,10-phenanthroline was also explored (dmphen), leading to the detection of characteristic fingerprints of distannoxanes 2 and 4 by 119Sn{119H} NMR, and to the crystallization of phenanthrolinium triflate salts, which were characterized by X-ray diffraction analysis as dmphenHOTf and dmphenHOTf·dmphen.

Despite recent tremendous progress in the synthesis of nonplanar chiral aromatics, and helicenes in particular, their conversion to half‐sandwich or sandwich transition metal complexes still lags behind, although they represent an attractive family of modular and underexplored chiral architectures with a potential catalytic use. In this work, starting from various chiral helicene‐indene proligands, we prepared the enantio‐ and diastereopure oxa[6]‐ and oxa[7]helicene‐indenido half‐sandwich RhI and RhIII complexes and oxa[7]helicene‐bisindenido ansa‐metallocene FeII complex. To document their use, oxahelicene‐indenido half‐sandwich RhIII complexes were employed as chiral catalysts in enantioselective C−H arylation of benzo[h]quinolines with 1‐diazonaphthoquinones to afford a series of axially chiral biaryls in mostly good to high yields and in up to 96 : 4 er. Thus, we developed stereocontrolled synthesis of chiral helicene‐indenido ansa‐ and half‐sandwich metal complexes, successfully demonstrated the first use of such helicene Cp‐related metal complexes in enantioselective catalysis, and described an unusual sequence of efficient central‐to‐helical‐to‐planar‐to‐axial chirality transfer. [ABSTRACT FROM AUTHOR]

Crystallization of [(Ph3Sn)2SeO4] ⋅ 1.5H2O in methanol leads to the formation of [{(Ph3Sn)2SeO4} ⋅ CH3OH]n (1) which constitutes a new specimen of organotin(IV) selenate derivatives. In the solid state, complex 1 is arranged in polymeric zig-zag chains, composed of alternating Ph3Sn and SeO4 groups. In addition, pendant Ph3Sn ⋅ CH3OH moieties are branched along chains according to a syndiotactic organization and via Sn-O-Se connections. From a supramolecular point of view, intermolecular hydrogen bonds established between the selenate groups (uncoordinated oxygen) and the hydroxyl functions (CH3OH) of the pendant groups link the chains together.

Electrochemical oxidation of Zn(II) 2,7,12,17‐tetra‐tert‐butylporphyrin in the presence of a series of azole derivatives (1‐methylimidazole, 1‐vinyl‐1H‐imidazole, 2‐(1H‐imidazol‐1‐yl)pyridine, 1‐methylbenzimidazole, 1‐methyl‐1H‐1,2,4‐triazole, and benzothiazole) affords the corresponding meso‐substituted azolium‐porphyrins in very mild conditions and good yields. It was found that these nucleophiles were strongly ligated to the zinc(II) azolium‐porphyrin complexes. Thus a demetalation/remetalation procedure was performed to recover the non‐azole‐coordinated zinc(II) complexes. X‐ray crystallographic structures of three azolium‐porphyrins were solved. Cyclic voltammetry analyses provided insight into the electron‐withdrawing effect of the azolium substituents. [ABSTRACT FROM AUTHOR]

Polytetrafluoroethylene (PTFE) and, by extension, fluoropolymers are ubiquitous in science, life, and the environment as perfluoroalkyl pollutants (PFAS). In all cases, it is difficult to transform these materials due to their chemical inertness. Herein, we report a direct amination process of PTFE and some fluoropolymers such as polyvinylidene fluoride (PVDF) and Nafion by lithium alkylamide salts. Synthesizing these reactants extemporaneously between lithium metal and an aliphatic primary di- or triamine that also serves as a solvent leads to the rapid nucleophilic substitution of fluoride by an alkylamide moiety when in contact with the fluoropolymer. Moreover, lithium alkylamides dissolved in suitable solvents other than amines can react with fluoropolymers. This highly efficient one-pot process opens the way for further surface or bulk modification if needed, providing an easy, inexpensive, and fast experiment protocol on large scales. [ABSTRACT FROM AUTHOR]

The direct palladium‐catalyzed C−H arylation of 1,3,4‐oxadiazoles with challenging aryl chloride substrates is promoted by the use of a specifically designed electron‐rich ferrocenyl diphosphane. This protocol employs 0.5 to 1.0 mol % catalyst loading without any additives such as copper or ammonium salts, and equally tolerates electron‐donating and electron‐withdrawing substituents on the (heteroaryl)aryl halides, as illustrated by the efficient synthesis in 86 % yield of the anti‐tubercular agent PHOXPY (2‐(5‐phenyl‐1,3,4‐oxadiazol‐2‐yl)pyrazine) by a late‐stage arylation using 2‐chloropyrazine. [ABSTRACT FROM AUTHOR]

Reaction of potassium hydrotris(pyrazol-1-yl)borate (KTp) and n-BuSnCl3 at room temperature led to the quantitative formation of TpSn(Cl)2(n-Bu) (1). Colorless single crystals were obtained from a mixture of toluene/dichloromethane and were characterized as TpSn(Cl)2(n-Bu)·½ toluene. Complex 1 crystallizes in the triclinic P1̅ space group, with Z=2, a=8.0496(8) Å, b=9.4867(9) Å, c=14.2710(14) Å, α=90.365(3)°, β=104.479(3)°, γ=95.066(3)°, and V=1050.60(18) Å3. Its structure exhibits a piano stool conformation involving a distorted octahedral geometry around the central Sn(IV) atom. In the crystal and from a supramolecular point of view, 1 is organized in pairs according to a V-shaped arrangement implicating pyrazolyl rings and through weak intermolecular interactions (π-π, C-H···π, and C-H···Cl). The structural analysis of 1 was completed by infrared and solution NMR spectroscopy measurements as well as elemental analysis, which confirm the X-ray elucidation.

The reaction of bis(2-methyl-1H-imidazol-3-ium) oxalate, [C4H7N2]2[C2O4], and bis(triphenyltin) oxalate, [(Ph3Sn)2(C2O4)], in methanol at room temperature yielded the formation of 2-methyl-1H-imidazol-3-ium catena-O,O′-oxalatotriphenylstannate, [C4H7N2][Ph3Sn(C2O4)] (1), which crystallizes in the monoclinic space group P21/c with Z=8, a=16.9334(14) Å, b=17.3251(14) Å, c=14.5114(10) Å, β=90.590(2)°, and V=4257.0(6) Å3. The oxalate ligand of 1 displays a bridging coordination mode and thus links two SnPh3 moieties through an axial coordination leading to the propagation of infinite polymeric chains along the c axis. All Sn(IV) atoms exhibit a trigonal bipyramid geometry. The negative charge of [Ph3Sn(C2O4)]- moieties is compensated by the presence of surrounding noncoordinating 2-methyl-1H-imidazol-3-ium cations. From a supramolecular point of view, the Sn-based chains are connected to one another through N-H···O hydrogen bond interactions involving oxalate ligands of distinct strands and doubly by the [C4H7N2]+ cations. The topology of the resulting crystal packing can be described as a two-dimensional layer network.

The article in Angewandte Chemie discusses the stereocontrolled synthesis of chiral helicene-indenido ansa- and half-sandwich metal complexes for use in catalysis. Piano stool rhodium complexes derived from helicene-indene proligands can catalyze enantioselective C-H arylation, producing axially chiral biaryls with high yields and enantiomeric ratios. The research by Tereza Edlová, Irena G. Stará, Ivo Starý, and others highlights the unique transfer of central-to-helical-to-planar-to-axial chirality in these complexes. [Extracted from the article]

The article in Angewandte Chemie International Edition discusses the stereocontrolled synthesis of chiral helicene-indenido ansa- and half-sandwich metal complexes for use in catalysis. The research by Tereza Edlová, Irena G. Stará, Ivo Starý, and others focuses on piano stool rhodium complexes derived from helicene-indene proligands, which can catalyze enantioselective C-H arylation to produce axially chiral biaryls with high yields and enantiomeric ratios. The study highlights an unusual sequence of central-to-helical-to-planar-to-axial chirality transfer in these complexes. [Extracted from the article]

The article in ChemSusChem discusses the first synthesis of azolium porphyrins through electrosynthesis. By oxidizing a ZnII porphyrin at its first oxidation potential in the presence of azole nucleophiles, cationic porphyrins are produced with high regioselectivity under mild conditions. The research was conducted by a team of authors including S. Richeter, C. H. Devillers, and others. [Extracted from the article]

C−H arylation of 1‐pyrenylphosphine derivatives catalyzed by rhodium and directed by a diphenylphosphino group is selectively achieved at the K‐region, i. e. 4‐, 5‐, 9‐, or 10‐position of the pyrene moiety. This peri C−H activation/arylation of pyrenes using (hetero)aryl bromide coupling partners tolerates both electron‐donating and electron‐withdrawing groups on the arene, and provides isolated yields of products between 25% to 90%, including from bulky polyaromatic bromoarene substrates. We achieved investigations directed at the formation and reactivity of pertinent intermediate species in this C−H arylation reaction. The P‐ligand coordination at rhodium was established using 31P NMR and XRD analysis, and we isolated five‐membered rhodacycles as intermediates to the directed C−H functionalization. The data obtained overall supported the occurrence of a cationic rhodium catalytic process. We further described the access to a large class of pyrenylphosphine ligands and their selenated derivatives. Phosphine selenation allows to rapidly estimate from 1JP=Se values the basic character of the ligand in the perspective of their use for coordination. Accordingly, linear P‐coordinated Au(I) gold complexes were isolated, in addition to the variously coordinated Rh(III) complexes. The present methodology significantly extends the scope of polyaromatics that are functionalizable at the K‐Region by direct C−H activation, beyond smaller‐sized naphtalenes and aminopyrenes. [ABSTRACT FROM AUTHOR]