797-70-6Relevant academic research and scientific papers
Conversion from Heterometallic to Homometallic Metal–Organic Frameworks
Song, Jeong Hwa,Lee, Giseong,Yoon, Jung Heum,Jang, Junyeon,Choi, Doosan,Yun, Heejun,Kwon, Kangin,Kim, Hojin,Hong, Chang Seop,Kim, Youngki,Han, Hogyu,Lim, Kwang Soo,Lee, Woo Ram
, p. 11767 - 11775 (2020)
Two new heterometallic metal–organic frameworks (MOFs), LnZnTPO 1 and 2, and two homometallic MOFs, LnTPO 3 and 4 (Ln=Eu for 1 and 3, and Tb for 2 and 4; H3TPO=tris(4-carboxyphenyl)phosphine oxide) were synthesized, and their structures and pro
N-heterocyclic carbene complexes of palladium in oxygen atom transfer reactions involving the making and breaking of N-O bonds
Cai, Xiaochen,Majumdar, Subhojit,Serafim, Leonardo F.,Temprado, Manuel,Nolan, Steven P.,Cazin, Catherine S.J.,Captain, Burjor,Hoff, Carl D.
, p. 285 - 293 (2017)
Reaction of three equivalents of MesCNO (Mes = 2,4,6-trimethylphenyl) with one equivalent of [Pd(IPr)(P(p-tolyl)3)] in toluene yields the solid complex [Pd(IPr)(NCMes)(κ2-O–N[dbnd]C-Mes(–N–C([dbnd]O)Mes))]. Three major steps are proposed to be involved in the reaction based on spectroscopic studies as well as literature precedents for related cycloadditions: i. oxidation of the coordinated phosphine ligand to phosphine oxide ii. oxygen atom transfer forming a C[dbnd]O bond from the N–O bond of MesCNO, and iii. cycloaddition of a final MesCNO ligand to yield product. Addition of two equivalents of [rad]NO at low temperature to the in situ generated peroxide complex [Pd(IPr)2(η2-O2)] generates the N-bonded complex trans-[Pd(IPr)2(NO2)2] in keeping with a literature precedent reported for similar complexes. Insight into the energetics of this reaction are probed by DFT calculations using the truncated ligand complex [Pd(IMe)2]. The computed enthalpy of binding of two moles of [rad]NO2 to form [Pd(IMe)2(NO2)2] is ?112 kcal/mol indicating that its preparation from [Pd(IMe)2], N2 and 2O2 is thermodynamically favorable by ?96 kcal/mol. Crystal structures of [Pd(IPr)(NCMes)(κ2-O–N[dbnd]C-Mes(–N–C([dbnd]O)Mes))] and trans-[Pd(IPr)2(NO2)2] are reported.
A Mononuclear Non-Heme Manganese(III)-Aqua Complex in Oxygen Atom Transfer Reactions via Electron Transfer
Sharma, Namita,Zou, Huai-Bo,Lee, Yong-Min,Fukuzumi, Shunichi,Nam, Wonwoo
, p. 1521 - 1528 (2021/02/01)
Metal-oxygen complexes, such as metal-oxo [M(O2-)], -hydroxo [M(OH-)], -peroxo [M(O22-)], -hydroperoxo [M(OOH-)], and -superoxo [M(O2?-)] species, are capable of conducting oxygen atom transfer (OAT) reactions with organic substrates, such as thioanisole (PhSMe) and triphenylphosphine (Ph3P). However, OAT of metal-aqua complexes, [M(OH2)]n+, has yet to be reported. We report herein OAT of a mononuclear non-heme Mn(III)-aqua complex, [(dpaq)MnIII(OH2)]2+ (1, dpaq = 2-[bis(pyridin-2-ylmethyl)]amino-N-quinolin-8-yl-acetamidate), to PhSMe and Ph3P derivatives for the first time; it is noted that no OAT occurs from the corresponding Mn(III)-hydroxo complex, [(dpaq)MnIII(OH)]+ (2), to the substrates. Mechanistic studies reveal that OAT reaction of 1 occurs via electron transfer from 4-methoxythioanisole to 1 to produce the 4-methoxythioanisole radical cation and [(dpaq)MnII(OH2)]+, followed by nucleophilic attack of H2O in [(dpaq)MnII(OH2)]+ to the 4-methoxythioanisole radical cation to produce an OH adduct radical, 2,4-(MeO)2C6H3S?(OH)Me, which disproportionates or undergoes electron transfer to 1 to yield methyl 4-methoxyphenyl sulfoxide. Formation of the thioanisole radical cation derivatives is detected by the stopped-flow transient absorption measurements in OAT from 1 to 2,4-dimethoxythioanisole and 3,4-dimethoxythioanisole, being compared with that in the photoinduced electron transfer oxidation of PhSMe derivatives, which are detected by laser-induced transient absorption measurements. Similarly, OAT from 1 to Ph3P occurs via electron transfer from Ph3P to 1, and the proton effect on the reaction rate has been discussed. The rate constants of electron transfer from electron donors, including PhSMe and Ph3P derivatives, to 1 are fitted well by the electron transfer driving force dependence of the rate constants predicted by the Marcus theory of outer-sphere electron transfer.
Microwave assisted P–C coupling reactions without directly added P-ligands
Henyecz, Réka,Huszár, Bianka,Keglevich, Gy?rgy,Mucsi, Zoltán
, (2021/12/24)
Our group introduced a green protocol for the Pd(OAc)2- or NiCl2-catalyzed P–C coupling reaction of aryl halides and various > P(O)H-compounds under MW conditions without directly added P-ligands. The reactivity of a few aryl derivatives in the Pd(OAc)2-catalyzed Hirao reaction was also studied. An induction period was observed in the reaction of bromobenzene and diphenylphosphine oxide. Finally, the less known copper(I)-promoted P–C coupling reactions were investigated experimentally. The mechanism was explored by quantum chemical calculations.
Synthesis of Azaylide-Based Amphiphiles by the Staudinger Reaction
Kishida, Natsuki,Suzuki, Hayate,Toyota, Shinji,Yamashina, Masahiro,Yoshizawa, Michito
supporting information, p. 17915 - 17919 (2021/07/09)
Catalyst- and reagent-free reactions are powerful tools creating various functional molecules and materials. However, such chemical bonds are usually hydrolysable or require specific functional groups, which limits their use in aqueous media. Herein, we report the development of new amphiphiles through the Staudinger reaction. Simple mixing of chlorinated aryl azide with a hydrophilic moiety and various triarylphosphines (PAr3) gave rise to azaylide-based amphiphiles NPAr3, rapidly and quantitatively. The obtained NPAr3 formed ca. 2 nm-sized spherical aggregates (NPAr3)n in water. The hydrolysis of NPAr3 was significantly suppressed as compared with those of non-chlorinated amphiphiles nNPAr3. Computational studies revealed that the stability is mainly governed by the decrease in LUMO around the phosphorus atom owing to the o-substituted halogen groups. Furthermore, hydrophobic dyes such as Nile red and BODIPY were encapsulated by the spherical aggregates (NPAr3)n in water.
Palladium-Catalyzed C-P Bond-Forming Reactions of Aryl Nonaflates Accelerated by Iodide
McErlain, Holly,Riley, Leanne M.,Sutherland, Andrew
, p. 17036 - 17049 (2021/11/18)
An iodide-accelerated, palladium-catalyzed C-P bond-forming reaction of aryl nonaflates is described. The protocol was optimized for the synthesis of aryl phosphine oxides and was found to be tolerant of a wide range of aryl nonaflates. The general nature of this transformation was established with coupling to other P(O)H compounds for the synthesis of aryl phosphonates and an aryl phosphinate. The straightforward synthesis of stable, isolable aryl nonaflates, in combination with the rapid C-P bond-forming reaction allows facile preparation of aryl phosphorus target compounds from readily available phenol starting materials. The synthetic utility of this general strategy was demonstrated with the efficient preparation of an organic light-emitting diode (OLED) material and a phosphonophenylalanine mimic.
One-pot cascade ring enlargement of isatin-3-oximes to 2,4-dichloroquinazolines mediated by bis(trichloromethyl)carbonate and triarylphosphine oxide
Qin, Jinjing,Li, Zhenhua,Ma, Shengzhe,Ye, Lixian,Jin, Guoqiang,Su, Weike
supporting information, p. 1007 - 1012 (2020/07/10)
An efficient and convenient one-pot cascade synthesis of 2,4-dichloroquinazolines directly from isatin-3-oximes with the addition of bis(trichloromethyl)carbonate and triarylphosphine oxide was developed, leading to substituted quinazolines in moderate to excellent yields. The efficiency of this transformation was demonstrated by compatibility with a range of functional groups. Thus, the method represents a convenient and practical strategy for the synthesis of substituted 2,4-dichloroquinazolines.
Di(hydroperoxy)cycloalkane Adducts of Triarylphosphine Oxides: A Comprehensive Study including Solid-State Structures and Association in Solution
Arp, Fabian F.,Bhuvanesh, Nattamai,Blümel, Janet
, p. 13719 - 13732 (2020/10/02)
Four new di(hydroperoxy)cycloalkane adducts (Ahn adducts) of p-Tol3PO (1) and o-Tol3PO (2), namely, p-Tol3PO·(HOO)2C(CH2)5 (3), o-Tol3PO·(HOO)2C(CH2)5 (4), p-Tol3PO·(HOO)2C(CH2)6 (5), and o-Tol3PO·(HOO)2C(CH2)6 (6), have been synthesized and fully characterized. Their single crystal X-ray structures have been determined and analyzed. The 31P NMR data are in accordance with hydrogen bonding of the di(hydroperoxy)alkanes to the P═O groups of the phosphine oxides. Due to their high solubility in organic solvents, natural abundance 17O NMR spectra of 1-6 could be recorded, providing the signals for the P═O groups and additionally the two different oxygen nuclei in the O-OH groups in the adducts 3-6. The association and mobility of 3-6 were explored by 1H DOSY (diffusion ordered spectroscopy) NMR, which indicated persistent hydrogen bonding of the adducts in solution. Competition experiments with phosphine oxides allowed ranking of the affinities of the di(hydroperoxy)cycloalkanes for the different phosphine oxide carriers. On the basis of variable temperature 31P NMR investigations, the Gibbs energies of activation ΔG? for the adduct dissociation processes of 3-6 at different temperatures, as well as the enthalpy ΔH? and entropy ΔS? of activation, have been determined. IR spectroscopy of 3-6 corroborated the hydrogen bonding, and in the Raman spectra, the ν(O-O) stretching bands have been identified, confirming the presence of peroxy groups in the solid materials. The high solubilities in selected organic solvents have been quantified.
Photooxidation of triarylphosphines under aerobic conditions in the presence of a gold(iii) complex on cellulose extracted from Carthamus tinctorius immobilized on nanofibrous phosphosilicate
Sadeghzadeh, Seyed Mohsen,Zhiani, Rahele
, p. 1509 - 1516 (2019/01/24)
Triarylphosphines were converted to the corresponding oxides via photooxidation as a novel method. In this study, cellulose was extracted from the Carthamus tinctorius plant and then oxidized by sodium metaperiodate. A gold complex was supported on this natural cellulose. Then, a gold complex on natural cellulose supported on FPS (FPS/Au(iii)) was synthesized for the reduction of phosphine oxides to corresponding phosphines with remarkable chemoselectivity. The morphology of FPS led to higher catalytic activity. FPS/Au(iii) NPs were thoroughly characterized using TEM, FESEM, FTIR, TGA, and BET.
Visible light-induced 4-phenylthioxanthone-catalyzed aerobic oxidation of triarylphosphines
Ding, Aishun,Li, Shijie,Chen, Yang,Jin, Ruiwen,Ye, Cong,Hu, Jianhua,Guo, Hao
supporting information, p. 3880 - 3883 (2018/09/27)
We report herein a visible light-induced oxidation of triarylphosphines under aerobic condition with excellent functional group tolerance. In this transformation, the photo catalyst 4-phenylthioxanthone acted as a photosensitizer for the in situ generation of singlet oxygen. This new approach provided a cheaper and greener method for the preparation of phosphine oxide, showing great advantages in environmental protocols.
