Organo–Phosphorus–Sulfur Heterocycles by Reactions of Phenylphosphine with Ketones

Abstract

The reaction of phenylphosphine (PhPH₂) with ketones showed conversion into a 5-membered heterocyclic ring of the type P₂SOC if 2–2.5 equivalents of sulfur (S₈) were used. X-Ray data and ³¹P, ¹³C, ¹H NMR spectra proved the formation of the (Z) diastereomer of 1,3,2,4-oxathiadiphospholane 1 ((PhPS)₂SOCMe₂) if acetone is used. Mechanistic studies displayed that small changes in the reaction pathway lead toward the formation and characterization of intermediates including 1,3,2,4,5-dithiatriphospholane, 2,4,5-triphenyl-2-sulfide (PhP)₃S₃ and 1,3,2,4-oxathiadiphospholane, and 5,5-dimethyl-2,4-diphenyl-2-sulfide ((PhPS)(PhP)SOCMe₂), which undergo reactions with acetone, subsequently yielding the abovementioned heterocyclic ring.     

N,P掺杂型C@Mo_2C催化剂的制备及其催化CO_2加氢反应研究

以三聚氰胺苯甲酸盐为碳源和氮源、以三聚氰胺磷钼酸盐为钼源、磷源和氮源,采用程序升温的方法制备了系列N,P掺杂型C@Mo_2C催化剂。采用XRD、SEM、TEM和XPS等对催化剂的结构、形貌和表面特性进行了表征,研究了三聚氰胺苯甲酸盐中n(三聚氰胺)/n(苯甲酸)、前驱体中n(C)/n(Mo)等因素对所制备催化剂的结构及其在二氧化碳加氢反应中催化性能的影响。在反应温度为220℃、反应压力为3.0 MPa、空速为3 600 m L/(g·h)的条件下,在N,P掺杂型C@Mo_2C的催化作用下,CO_2转化率可以达到12.2%,此时产物中CH_3OH的选择性达到52.2%。     

Synthesis of 4,5-decamethyleneimidazole, 4,5-decamethyleneoxazole, 4,5-decamethyleneisoxazole, 4,5-decamethyleneimidazolone-2, and 4,5-decamethylenepyrazole from cyclododecanone derivatives

4,5-Decamethyleneimidazole, 4,5-decamethyleneoxazole, and 4,5-decamethyleneimidazolone-2 were synthesized by reactions of 2-bromocyclododecanone and 2-hydroxycyclododecanone with formamide, ammonium formate, and urea, respectively. Condensation of 2-formylcyclododecanone with hydroxylamine and hydrazine hydrate resulted in 4,5-decamethyleneisoxazole, and 4,5-decamethylenepyrazole, respectively.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 891–893, May, 1994.     

Reactions of α-halo-α, β-unsaturated aldehydes with secondary amines

Reactions of 2-halo-2-alkenals R(R)C=CX-CHO with secondary amines R₂NH occur asipso-substitution of the halogen atom, along with fragmentation and condensation, yielding 1,2-diaminoethenes R₂NCH=CHNR₂, carbonyl compounds RC(O)R, 1,3-bis(amino)-2-haloolefins R(R)C(NR₂)CX=CHNR₂, and formamides R₂NCHO. The ratio between the competing reactions depends on the structure of the starting compounds and the experimental conditions.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp, 135–138, January, I996.     

Syntheses and Olfactory Characters of Some Endo-α-Substituted-Bicyclo[2. 2. 2]-Octenyl (or Octanyl) Methanols

Sixteen title compounds were synthesized, twelve of which are new ones. Their structures were determined by 1H NMR, IR and MS, the refractive indices or melting points were measured. Odors of all the title compounds were evaluated and the structure-odor relationship was briefly discussed.     

单层含氧缺陷δ-MnO2用于二氧化碳还原

电催化还原二氧化碳成多碳燃料一直是研究的热点. 而找到活性高,选择性优,稳定性好的催化剂一直是研究者们奋斗的目标. 二氧化锰因其独特的物理和化学性质被广泛的应用于电催化领域,而缺陷的调控可以改变催化剂的电子性质,在此次工作中作者系统地研究了在有氧缺陷和没有氧缺陷的二维二氧化锰上的电催化二氧化碳还原反应. 通过利用自旋极化密度泛函理论,作者分别计算了他们的电子性质和分子在吸附过程中的能量值. 结果显示,缺陷的引入改变了二氧化锰的特性,使其从半导体性质变为半金属性质,从而提高催化剂的导电性. 同时,分析能量图也很容易发现对应产品的选择性也发生了变化. 二氧化锰有利于甲酸的产生,而氧缺陷的二氧化锰更有利于一氧化碳的生成. 本研究将为二氧化碳还原的其他非贵金属氧化物催化剂的结构设计和优化提供一定的指导.     

Native Structure-Based Peptides as Potential Protein–Protein Interaction Inhibitors of SARS-CoV-2 Spike Protein and Human ACE2 Receptor

Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) is a positive-strand RNA virus that causes severe respiratory syndrome in humans, which is now referred to as coronavirus disease 2019 (COVID-19). Since December 2019, the new pathogen has rapidly spread globally, with over 65 million cases reported to the beginning of December 2020, including over 1.5 million deaths. Unfortunately, currently, there is no specific and effective treatment for COVID-19. As SARS-CoV-2 relies on its spike proteins (S) to bind to a host cell-surface receptor angiotensin-converting enzyme-2(ACE2), and this interaction is proved to be responsible for entering a virus into host cells, it makes an ideal target for antiviral drug development. In this work, we design three very short peptides based on the ACE2 sequence/structure fragments, which may effectively bind to the receptor-binding domain (RBD) of S protein and may, in turn, disrupt the important virus-host protein–protein interactions, blocking early steps of SARS-CoV-2 infection. Two of our peptides bind to virus protein with affinity in nanomolar range, and as very short peptides have great potential for drug development.     

C2(a 3Πu)+NO的反应机理研究

The reaction mechanism of C2（a 3Πu）+ NO is investigated at the level of G2（CC,MP2）. The equilibrium geometries,harmonic frequencies and energy of various stationary points on the potential energy surfaces have been calculated in the lowest doublet states. It is found that there are two reaction mechanisms:one is CCON mechanism that begins from O atom of NO attacks C2 and the intermediate is CCON;the other is called CCNO mechanism for its intermediate is CCNO formed by N atom of NO attacks C2 . In the same time,the five possible ground product pathways corresponding to these two mechanisms for this reaction are analysed and concluded that the pathway that O atom of NO attacks C2 to produce the major products CN+CO via CCNO mechanism is the most favorable pathway.     

Kristallstruktur und Eigenschaften von Calcium- und Strontiumhexathiodiphosphat(IV), Ca2P2S6 und Sr2P2S6, mit einem Beitrag zu Ca5P8 und Pb2P2S6

Crystal Structure and Properties of Calcium and Strontium Hexathiodiphosphate(IV), Ca₂P₂S₆ and Sr₂P₂S₆, with a Contribution on Ca₅P₈ and Pb₂P₂S₆ Ca₂P₂S₆ and Sr₂P₂S₆ were prepared from metal and a mixture of red phosphorus and sulfur (molar ratio M:P:S = 1:1:3) in 2 corundum crucibles inserted in quartz ampullae under vacuum (20 d 900°C). The compounds were obtained as colourless, crystalline powders containing single crystals. They crystallize in the Sn₂P₂S₆ (high temperature form) type structure (P2₁/c, Z = 2): Ca₂P₂S₆ a = 653.2(2)pm, b = 728.1(2)pm, c = 1110.1(4)pm, β = 124.00(4)°, d = 2.50(2); Sr₂P₂S₆ a = 664.3(2)pm, b = 755.7(3)pm, c = 1139.7(3)pm, β = 124.07(2)°, d = 2.97(2). The anions P₂S have staggered confirmation and are arranged with the motif of a cubic close-packing. Sr²⁺ is coordinated by 8S which form a twofold face-capped trigonal prism and belong to 4P₂S. Structure calculations clearly show that Pb₂P₂S₆ also crystallizes in P2₁/c and not in Pc [1]. Also, Raman- and IR-spectra of Ca₅P₈ were recorded at 20°C. The stretching vibrations of P were assigned in analogy to those of P₂S in alkaline earth hexathiodiphosphates(IV). The range of their frequencies (480 to 340 cm^?1) is essentially smaller and shifted to smaller values compared with P₂S in Ca₂P₂S₆ and Sr₂P₂S₆ (620 to 390 cm^?1). The symmetry of P is not D_3d but C_2h as in the case of P₂S.     

NiWS/γ-Al2O3催化剂上吲哚加氢脱氮反应:H2S和喹啉的影响

在连续固定床微反装置上考察了吲哚（IND）和1,2-二氢吲哚（HIN）在NiWS/γ-Al₂O₃催化剂上加氢脱氮（HDN）的反应以及 H₂S和喹啉（Q）对其加氢脱氮反应的影响。结果表明,碱性含氮化合物HIN较吲哚对其自身的加氢脱氮反应抑制作用更为明显。H₂S能够促进HIN的C（sp³）－N断裂,但抑制了邻乙基苯胺（OEA）的 C（sp²）－N断裂;同时吲哚加氢反应途径也受到了抑制。喹啉的添加严重降低了吲哚加氢脱氮反应的转化率和脱氮率;喹啉对吲哚加氢反应和C－N键断裂反应均产生明显的抑制作用。喹啉的抑制作用主要源于喹啉及其中间产物1,2,3,4-四氢喹啉（THQ1）和5,6,7,8 -四氢喹啉（THQ5）与吲哚及其中间产物的竞争吸附。     

New fluorinated isoxazolidines

A simple procedure for the synthesis of fluorinated isoxazolidines from perfluoro-2-methylpent-2-ene and aliphatic aldoximes is described.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1449–1451, August, 1994.     

Reactions of 1,3,2-dioxaphospholane derivatives with thiocyanatoalcohols

The reactions of 2-dimethylamino-, 2-methoxy-, 2-chloro-4,5-dimethyl-1,3,2-dioxaphos-pholanes with 4-thiocyanato-2-butanol in all cases yield 2-(1-methyl-3-thiocyanatopropoxy)-4,5-dimethyl-1,3,2-dioxaphospholane. The latter reacts with elemental sulfur to form the corresponding thiophosphate.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2130–2131, December, 1993.     

Cycloaddition reaction of quadricyclane and fluoroolefins

Reaction of quadricyclane (1) with fluoroolefins of different structure results in stereoselective formation of polyfluorinated exo-tricyclo[4.2.1.0^2,5]non-7-enes. The reaction of a mixture of trans/cis CF₃CFCFCF₃ with 1 is stereoselective and the resulting cycloadducts 7a, b preserve the original alkene stereochemistry. The relative rate constants of cycloaddition of a series of fluoroolefins to 1 under pseudo first-order conditions measured by kinetic NMR at 109 °C provide a kinetic scale of reactivities of the fluoroolefins in this reaction.These relative rate constants correlate well with the number of fluoroalkyl groups connected to the double bond, reaching a maximum for the tri-substituted olefin: CF₃CFCF₂:CF₃CFCFCF₃:(CF₃)₂CC(CF₃)₂:(CF₃)₂CCFC₂F₅ = 1:1.2-1.9:4:138.     

RuH2和RuN2电子组态与光谱性质的从头计算

Using DFT method at B3LYP / 6-311G** level,the possible electronic states of RuH2 and RuN2 have been calculated,including the chemical adsorption and physical adsorption. For the RuH2 cluster,electronic states 3B2 and 5Σ- correspond to the physical adsorption. The RuN2 calculation results were also compared with the experimental values on ruthenium single crystal surfaces. It is found that the single states and the triplet states are in good agreement with the experimental values. For the C∞v symmetry,the calculated frequency of the quintuple state 5Σ- is slightly lower than the experimental value. For the C2v symmetry,the frequencies of the quintuple states are much lower than the experiment value and the 3B2 and 5A1 states are unstable.     

焙烧温度对TiO2-ZrO2复合氧化物性质及其对十八醇脱水制十八烯反应性能的影响

通过在ZrO_2中掺杂TiO_2,并在350-500℃下焙烧,制备了系列TiO_2-ZrO_2复合氧化物催化剂,将其应用于十八醇脱水制十八烯反应。随焙烧温度的升高,催化剂表面的Lewis酸性位量逐渐增加,450℃焙烧的催化剂Lewis酸性位量最多,焙烧温度继续升高则Lewis酸性位量降低;催化剂中未发现Br?nsted酸性位。焙烧温度≤400℃的TiO_2-ZrO_2复合氧化物形成Ti-O-Zr键,呈无定形态;焙烧温度400℃的TiO_2-ZrO_2复合氧化物呈单斜相和四方相ZrO_2晶型。晶相结构和酸性位量综合影响催化剂的十八醇脱水性能,具有单斜相和四方相ZrO_2晶型的催化剂上酸性位活性很低,具有无定形相的催化剂上酸性位活性显著增加,400℃焙烧的催化剂1-十八烯收率最高。     

硅胶负载钒磷氧化物催化2,6-二氯甲苯氨氧化反应

对硅胶负载钒磷氧化物（ＶＰＯ）催化剂（ｎ（Ｖ）／ｎ（Ｐ）＝１）催化２,６－二氯甲苯（ＤＣＴ）氯氧化反应进行了研究。考察了反应温度、空气／ＤＣＴ比和氨／ＤＣＴ比等因素对反应的影响。反应温度对氨氧化反应影响较大,空气／ＤＣＴ比和氨／ＤＣＴ比对反应的影响很大。最佳反应条件为：Ｔ＝６７３Ｋ,ｎ（ａｉｒ）／ｎ（ＤＣＴ）＝３０,ｎ（ＮＨ３）／ｎ（ＤＣＴ）＝６．在此条件下,ＤＣＴ转化率为９０％,产率为５７％。与     

β-MnO2和α-Mn2O3纳米棒的自牺牲模板法制备、 表征和应用

在150 ℃下, 仅以高锰酸钾溶液和无水乙醇为原料, 通过水热反应合成前驱体γ-MnOOH纳米棒. 以γ-MnOOH纳米棒为自牺牲模板, 分别在350和600 ℃下煅烧90 min, 制备出高纯度的β-MnO₂和α-Mn₂O₃纳米棒. 采用X射线粉末衍射(XRD)、 扫描电子显微镜(SEM)及热重分析(TGA)等对所制备的样品进行表征. 结果表明, 前驱物γ-MnOOH为高纯度的纳米棒状晶体, 直径约100~300 nm, 长度可达数微米, 且终产物β-MnO₂和α-Mn₂O₃均具有较高的纯度, 也很好地保持了前驱物的纳米棒状结构. 以二者为锰源, 通过固相反应合成出尖晶石LiMn₂O₄正极材料. 当充放电倍率为0.5 C时, 其首次放电比容量分别可达到120.4和123.9 mA·h/g, 而且表现出良好的循环性能和倍率性能.     

锂分子里德堡态和双激发态的重新分类

根据里德堡轨道的类氢nλ特性,对 7Li2实验已观测到的和理论计算给出的68个电子态进行了分类,把这些态划分为核实贯穿里德堡态和核实非贯穿里德堡态.讨论了双电子激发态和里德堡态的微扰,也讨论了这种分类的意义.     

Pd/γ-Al2O3-TiO2催化剂上乙醇乙醛的催化氧化性能研究

采用混胶法和机械混合等方法制备了Pd质量分数为1%的Pd/γ-Al₂O₃-TiO₂催化剂,并对其催化活性、影响条件进行了考察。结果说明,由混胶法制备的Pd/γ-Al₂O₃-TiO₂催化剂对乙醇和乙醛的完全氧化表现出优异的催化性能,其活性明显高于单一载体催化剂Pd/TiO₂和Pd/Al₂O₃,150℃时乙醇和乙醛的转化率分别达到98.9%和98.5%。在较宽温度范围内和高空速条件下表现出良好的稳定性。同时运用XRD、TEM和FT-IR等技术对催化剂进行了表征。结果表明,在Pd/γ-Al₂O₃-TiO₂催化剂中Al₂O₃与TiO₂之间存在着较强的相互作用,使γ-Al₂O₃-TiO₂的比表面积和孔容积均调变到一个适中的数值,同时在催化剂表面Al₂O₃参与形成了有利于其催化活性的表面结构。