Tag: M.W=350-400

Zhang, Jing published the artcileElectron-Rich, Bulky Ruthenium PNP-Type Complexes. Acceptorless Catalytic Alcohol Dehydrogenation, Formula: C23H43NP2, the publication is Organometallics (2004), 23(17), 4026-4033, database is CAplus.

Reaction of the electron-rich, bulky tridentate PNP ligand (2,6-bis-(di-tert-butylphosphinomethyl)pyridine) with Ru(PPh₃)₃Cl₂ at 65° gave a solution containing the dinitrogen monomeric Ru(II) complex, Ru(PNP)(N₂)Cl₂ (1a), and the N₂-bridged dinuclear Ru(II) complex, [Ru(PNP)Cl₂]₂(μ-N₂) (1b), which can be interconverted. Passing Ar through the solution gave pure 1b. The Ru(II) hydride dinitrogen complex, [Ru(PNP)N₂(Cl)(H)] (2), was obtained by the reaction of complex 1b with 2 equiv of NaBEt₃H. Complex 1b reacted with 4 equiv of AgOCOCF₃ to yield [Ru(PNP)(CF₃COO)₂], 3. The Ru(II) carbonyl hydride complex, [Ru(PNP)H(OAc)₂] (4) was obtained by the reaction of PNP and Ru₂(OAc)₄ in MeOH as a result of O-H activation and decarbonylation of MeOH. Complexes 1b, 2, and 4 were structurally characterized by x-ray crystallog. Complexes 1b and 2 catalyze the dehydrogenation of secondary alcs. to the corresponding ketones with good yields and high selectivity accompanied with the evolution of dihydrogen in a homogeneous system without a need for a H acceptor. The presumed intermediate Ru dihydride complex is generated in situ by reaction 1b or 2 with a base (1 equiv for each Ru-Cl bond), and the reaction can proceed in the absence of excess base or acid.

Organometallics published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C8H16O2, Formula: C23H43NP2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Zhang, Jing published the artcileIron(II) complexes based on electron-rich, bulky PNN- and PNP-type ligands, Recommanded Product: 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, the publication is Inorganica Chimica Acta (2006), 359(6), 1955-1960, database is CAplus.

Reaction of the PNN ligand ((2-(di-tert-butylphosphinomethyl)-6-diethylaminomethyl)pyridine) with 1 equiv of anhydrous FeCl₂ in THF gave (PNN)FeCl₂ (1). The cationic complex [(PNN)Fe(THF)Cl](PF₆) (2) was obtained by chloride abstraction from 1 with 1 equiv of TlPF₆. Similarly, the PNP-type complexes, (t-Bu-PNP)FeCl₂ (3) and (i-Pr-PNP)FeCl₂ (4) were obtained from FeCl₂ with 1 equiv of t-Bu-PNP (2,6-bis(di-tert-butylphosphinomethyl)pyridine) and i-Pr-PNP (2,6-bis(di-iso-propylphosphinomethyl)pyridine), resp. Complexes 1 and 3 were characterized by x-ray diffraction and elemental analyses. In both structures the Fe(II) centers exhibit a distorted square pyramidal geometry comprising two chloride ligands and one tridentate PNN or PNP ligand. The magnetic properties of the paramagnetic complexes 1–4 are discussed.

Inorganica Chimica Acta published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C14H10N2O, Recommanded Product: 2,6-Bis((di-tert-butylphosphino)methyl)pyridine.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Simler, Thomas published the artcileDirect synthesis of doubly deprotonated, dearomatised lutidine PNP Cr and Zr pincer complexes based on isolated K and Li ligand transfer reagents, Category: pyridine-derivatives, the publication is Dalton Transactions (2016), 45(7), 2800-2804, database is CAplus and MEDLINE.

Chromium and zirconium complexes with dearomatized double deprotonated 2,6-bis[(di-tert-butylphosphino)methyl]pyridine were prepared by transmetalation of potassium and lithium salts. Double deprotonation of 2,6-bis-(di-tert-butylphosphinomethyl)-pyridine (^tBuPN^tBuP), with KCH₂C₆H₅ afforded K₂(^tBuP*N_a^tBuP*), N_a = anionic amido N, ^tBuP* = di-tert-Bu vinylic P donor. The analogous [Li₂(^tBuP*N_a^tBuP*)]₂ (1) was reacted with [CrCl₂(THF)₂] and [ZrCl₄(THT)₂] to give the helical [Cr{Cr(^tBuP*N_a^tBuP*)Cl}₂] (2) and [Zr(^tBuP*N_a^tBuP*)Cl₂] (3), resp. DFT calculations support dearomatization of P*N_aP* and its high donor ability.

Dalton Transactions published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C10H16Br3N, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Shahzadi, Hafiza Tayyaba published the artcileIridium-Catalyzed C-H Borylation of CF₃-Substituted Pyridines, Related Products of pyridine-derivatives, the publication is ACS Omega (2022), 7(13), 11460-11472, database is CAplus and MEDLINE.

Iridium-catalyzed C-H borylation of CF₃-substituted pyridines is described in this paper. The boronic ester group can be installed on the α, β, or γ position of pyridine by an appropriate substitution pattern. Sterically governed regioselectivity provides convenient access to a variety of CF₃-substituted pyridylboronic esters. These catalytic C-H borylation reactions were carried out neatly without the use of any solvent. Several functional groups, such as halo, ester, alkoxy, amino, etc., are compatible with this methodol. These pyridylboronic esters are amenable to column chromatog. and the products were isolated in good to excellent yields. α-Borylated pyridines, although isolated in good yields, do not have a long shelf life. The boronic ester derivatives of these CF₃-substituted pyridines can serve as useful precursors in the synthesis regime.

ACS Omega published new progress about 1256360-49-2. 1256360-49-2 belongs to pyridine-derivatives, auxiliary class Trifluoromethyl,Pyridine,Fluoride,Bromide,Boronic acid and ester,Boronate Esters,Boronic Acids,Boronic acid and ester, name is 2-Bromo-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-6-(trifluoromethyl)pyridine, and the molecular formula is C8H8BNO2, Related Products of pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Weitz, Ernst published the artcileFree ammonium radicals. VI. Radicals and meriquinonoid compounds. I. The dipyridinium subhalides, Application In Synthesis of 47369-00-6, the publication is Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen (1926), 432-45, database is CAplus.

cf. C. A. 18, 2168. It was suggested in the earlier paper that the deeply colored compounds assumed by other investigators to be dimeric quinhydrones (I) consisting of 1 mol. dipyridinium dihalide + 1 mol. dihydrodipyridyl (II) are in reality monomol. mono- or subhalides (III) of the dipyridinium radical (IV), a valence-tautomeric form of II. Mol. weight determinations of dibenzylpyridinium subchloride (V) in boiling MeOH gave mean values corresponding to 0.5 that calculated for III, indicating that the V in solution is almost completely ionized into IV and Cl^–; these determinations have been repeated in a perfected apparatus, in which the mol. weight of N,N’-diphenyldipyridinium subchloride (VI) has also been determined; the new determinations fully confirm the older observations. The higher result for V obtained by Emmert, Jungek and Häffner (C. A. 19, 518), from which they conclude that it is a I and ionizes into 3 parts (complex cation and 2 Cl ions) are explained by the fact that they used more concentrated solutions To establish that in their own solutions there is only electrolytic dissociation and not “quinhydrone decomposition,” W. and F. determined whether Beer’s law held for their solutions of V, using a specially constructed apparatus which made it possible to exclude every trace of atm. O; no lightening in the color could be detected either on dilution or heating. The IV are assumed to be univalent radicals in which the “odd” electron oscillates about the 2 central γ-C atoms. The anion in “bridged” union with the 2 halves of the IV need not be taken into account in these considerations; (see structure) it may be fixed at any point of the mol. or crystal lattice, the necessary oscillation in the affinity distribution being taken care of by the “odd” electron. This conception of a vibrating electron, which differs from older oscillation theories, especially that of Baeyer, in that it is only electrons and not atoms which are assumed to vibrate, can be applied to many other so-called intramol. quinhydrones, i. e. to large classes of dyes like those of the Ph₃CH series. A N,N’-dibenzyl-γ,γ’-dipyridinium “two-thirds”-iodide, C₂₄H₂₂N₂I₂.2C₂₄H₂₂N₂ (VII), was occasionally obtained instead of the normal III on treating the radical with the diiodide, but the formation of this and similar polymol. compounds is not at all contrary to the monomol. formulation of the III, for both the dipyridinium salts (with their coordinately unsaturated N atoms) and the radicals have enough unsaturated positions at which addition of other mols. can take place. The b. p. apparatus was so constructed that the determinations could be made in an atm. (not in a current) of CO₂ exactly under atm. pressure. Using 0.93 as the b. p. constant of the MeOH, the mol. weight of Bz₂ was found in this apparatus to be 192-226 (mean of 11 determinations, 210; calculated, 210); of PhNHAc, 139-44 (mean of 6 determinations, 142; calculated 135); of V in N/17.1-N/47.0 solution, 172-220 (mean of 18 determinations, 197); in N/11.5-N/15.3 solution, 203-229 (mean of 4 determinations, 215; calculated for III/2, 187); of VI in N/21.3-N/22.9 solution, 172-6 (mean of 3 determinations, 174; calculated for III/2, 173). On the other hand, dibenzyldipyridinium dichloride gave mol. weights of 253, 243 and 238 for V 31.3, 15.6 and 41.7, resp. (calculated for C₂₄H₂₂N₂Cl₂/2, 204). That the III represent an entirely independent stage of oxidation is further confirmed by the fact that they dissolve without decomposition in AcOH (at room temperature) while the corresponding free radicals dissolve only with decomposition VI, prepared like the subiodide, forms steel-blue crystals with violet tinge and metallic luster. VII forms a dark violet, indistinctly crystalline mass.

Berichte der Deutschen Chemischen Gesellschaft [Abteilung] B: Abhandlungen published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C6H8N2, Application In Synthesis of 47369-00-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Pelczar, Elizabeth M. published the artcileUnusual Structural and Spectroscopic Features of Some PNP-Pincer Complexes of Iron, Category: pyridine-derivatives, the publication is Organometallics (2008), 27(22), 5759-5767, database is CAplus.

The authors report a structural, spectroscopic, and computational study of two ^tBuPNP (2,6-bis(di-tert-butyl-phosphinomethyl)pyridine) complexes of iron, (^tBuPNP)FeCl₂ (1) and (^tBuPNP)Fe(CO)₂ (3). Complex 1, (^tBuPNP)FeCl₂, also independently synthesized by Milstein, has unusually long iron-ligand bond distances. DFT calculations show that these are clearly attributable to its high-spin electronic structure, and in particular to occupancy of the strongly antibonding d_x²-y² orbital. The crystal structure of 3 reveals two unusual aspects: the geometry around the iron atom in 3 is much closer to square pyramidal (SQP; apical CO) than to trigonal bipyramidal (TBP), although five-coordinate Fe(0) complexes are generally expected to be TBP; also, Chirik et al. have reported that (^iPrPNP)Fe(CO)₂ has essentially a perfect TBP structure (^iPrPNP = 2,6-bis(di-isopropyl-phosphinomethyl)pyridine); and the apical carbonyl ligand in 3 deviates significantly from linearity (Fe-C-O = 171.9°). Addnl., complex 3 is intensely blue in color, which is unusual for an Fe(0) complex and also significantly different from the red color of Chirik’s (^iPrPNP)Fe(CO)₂ species. Results from DFT calculations reproduce and explain these structural and spectroscopic aspects as well as the contrast between 3 and its ^iPrPNP analog.

Organometallics published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C23H43NP2, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Evans, Jeffrey C. published the artcileAn electron spin resonance, ENDOR, and TRIPLE resonance study of methyl-substituted N,N’-diphenyl-4,4′-bipyridylium dichloride radical cations, COA of Formula: C22H18Cl2N2, the publication is Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) (1985), 315-18, database is CAplus.

The ESR and ENDOR spectra of the radical cations of the bipyridylium dichlorides I (R = H, Me, R¹ = R² = R³ = H; R = R² = R³ = H, R¹ = Me; R = R¹ = R³ = H, R² = Me; R = R² = R³ = Me, R¹ = H) (II–VI, resp.) in MeOH were studied over a range of temperatures Values for the hyperfine coupling constants at -40° are given. The radical cation concentrations of II–V decreased with decreasing temperature, this change being reversible, whereas that of VI did not. The reversible change with temperature is explained in terms of a monomer-dimer equilibrium, and the absence of such an equilibrium for VI is due to lack of planarity of the mol., because of steric hindrance between the Me groups and the pyridyl ortho protons. The thermodn. constants ΔG°, ΔH°, and ΔS°, obtained for the dimerization equilibrium, are reported.

Journal of the Chemical Society, Perkin Transactions 2: Physical Organic Chemistry (1972-1999) published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C22H18Cl2N2, COA of Formula: C22H18Cl2N2.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Elleraas, Jeff published the artcileConformational Studies and Atropisomerism Kinetics of the ALK Clinical Candidate Lorlatinib (PF-06463922) and Desmethyl Congeners, Recommanded Product: (R)-Methyl 2-(1-((2-amino-5-bromopyridin-3-yl)oxy)ethyl)-4-fluorobenzoate, the publication is Angewandte Chemie, International Edition (2016), 55(11), 3590-3595, database is CAplus and MEDLINE.

Lorlatinib (PF-06463922) is an ALK/ROS1 inhibitor and is in clin. trials for the treatment of ALK pos. or ROS1 pos. NSCLC (i.e. specific subsets of NSCLC). One of the laboratory objectives for this mol. indicated that it would be desirable to advance a mol. which was CNS penetrant in order to treat brain metastases. From this perspective, a macrocyclic template was attractive for a number of reasons. In particular, this template reduces the number of rotatable bonds, provides the potential to shield polar surface area and reinforces binding through a restricted conformation. All of these features led to better permeability for the mols. of interest and thus increased the chance for better blood brain barrier penetration. With a CNS penetrant mol., kinase selectivity is a key consideration particularly with regard to proteins such as TrkB, which are believed to influence cognitive function. Removal of the chiral benzylic Me substituent from lorlatinib was perceived as not only a means to simplify synthetic complexity, but also as a strategy to further truncate the mol. of interest. Examination of the NMR of the desmethyl analogs revealed that the compound existed as a mixture of atropisomers, which proved separable by chiral SFC. The individual atropisomers were evaluated through a series of in vitro assays, and shown to have a favorable selectivity profile when compared to lorlatinib. The challenge to develop such a mol. lies in the rate at which the atropisomers interchange dictated by the energy barrier required to do this. Here, we describe the synthesis of the desmethyl macrocycles, conformational studies on the atropisomers, and the kinetics of the interconversion. In addition, the corresponding conformational studies on lorlatinib are reported providing a hypothesis for why a single diastereomer is observed when the chiral benzylic Me group is introduced.

Angewandte Chemie, International Edition published new progress about 1454848-00-0. 1454848-00-0 belongs to pyridine-derivatives, auxiliary class Aromatic Fluorinated Building Blocks, name is (R)-Methyl 2-(1-((2-amino-5-bromopyridin-3-yl)oxy)ethyl)-4-fluorobenzoate, and the molecular formula is C15H14BrFN2O3, Recommanded Product: (R)-Methyl 2-(1-((2-amino-5-bromopyridin-3-yl)oxy)ethyl)-4-fluorobenzoate.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Gausas, Laurynas published the artcileEvaluation of Manganese Catalysts for the Hydrogenative Deconstruction of Commercial and End-of-Life Polyurethane Samples, Category: pyridine-derivatives, the publication is ChemSusChem (2022), 15(1), e202101705, database is CAplus and MEDLINE.

Polyurethane (PU) is a thermoset plastic that is found in everyday objects, such as mattresses and shoes, but also in more sophisticated materials, including windmills and airplanes, and as insulation materials in refrigerators and buildings. Because of extensive inter-cross linkages in PU, current recycling methods are somewhat lacking. In this work, the effective catalytic hydrogenation of PU materials is carried out by applying a catalyst based on the earth-abundant metal manganese, to give amine and polyol fractions, which represent the original monomeric composition In particular, Mn-^PhMACHO is found to catalytically deconstruct flexible foam, molded foams, insulation, and end-of-life materials at 1 weight% catalyst loading by applying a reaction temperature of 180°C, 50 bar of H₂, and 0.9 weight% of KOH in iso-Pr alc. The protocol is showcased in the catalytic deconstruction of 2 g of mattress foam using only 0.13 weight% catalyst, resulting in 90% weight recovery and a turnover number of 905.

ChemSusChem published new progress about 338800-13-8. 338800-13-8 belongs to pyridine-derivatives, auxiliary class Bis-phosphine Ligands, name is 2,6-Bis((di-tert-butylphosphino)methyl)pyridine, and the molecular formula is C23H43NP2, Category: pyridine-derivatives.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem

Geraskina, Margarita R. published the artcileThe Viologen Cation Radical Pimer: A Case of Dispersion-Driven Bonding, SDS of cas: 47369-00-6, the publication is Angewandte Chemie, International Edition (2017), 56(32), 9435-9439, database is CAplus and MEDLINE.

The π bonds between organic radicals have generated excitement as an orthogonal interaction for designing self-assembling architectures in water. A systematic investigation of the effect of the viologen cation radical structure on the strength and nature of the pimer bond is provided. A striking and unexpected feature of this π bond is that the bond strength is unchanged by substitution with electron-donating groups or withdrawing groups or with increased conjugation. Furthermore, the interaction is undiminished by sterically bulky N-alkyl groups. Theor. modeling indicates that strong dispersion forces dominate the interaction between the radicals, rationalizing the insensitivity of the bonding interaction to substituents: the stacking of polarizable π radicals leads to attractive dispersion forces in excess of typical dispersion interactions of small mols. and helps overcome the Coulombic repulsion of bringing two cationic species into contact.

Angewandte Chemie, International Edition published new progress about 47369-00-6. 47369-00-6 belongs to pyridine-derivatives, auxiliary class Pyridine,Salt,Benzene,Organic ligands for MOF materials,Nitrogen containing MOF ligands,Nitrogen containing MOF ligands, name is 1,1′-Diphenyl-[4,4′-bipyridine]-1,1′-diium chloride, and the molecular formula is C22H18Cl2N2, SDS of cas: 47369-00-6.

Referemce:
https://en.wikipedia.org/wiki/Pyridine,
Pyridine | C5H5N – PubChem