氟烷基化和氟烷氧基化的研究 19.铱(Ⅰ)催化下氟烷基碘与烯烃、炔烃的加成反应

在羰基-三(三苯基膦)氢化铱(Ⅰ)催化下,氟烷基碘1与烯烃2加成得到高产率的加成产物,反应条件温和,有良好的选择性.氟烷基碘1也可与炔烃4反应,生成以 E 式异构体占优势的氟烷基化烯烃.反应体系中加入自由基抑制剂或单电子转移阻止剂则大大减慢反应;二烯丙基醚可以捕获自由基生成四氢呋喃衍生物;光电子能谱表明部分一价铱在反应后价态升高,这些事实表明反应为单电子转移引发下的自由基链式机理.     

氟烷基化和氟烷氧基化的研究 钯(O)催化氟烷基碘对烯烃的加成反应

氟烷基碘通过光、热、自由基引发剂引发对烯烃加成。1984年Ojima等报道过渡金属羰基络合物也能催化氟烷基碘对重键的加成。我们前已报道铜在乙酐、二缩二乙二醇二甲醚(DG)或乙腈中通过单电子转移引发氟烷基碘与烯烃、炔烃反应,反应条件温和产率较高。但钯是否也能催化氟烷基碘与烯烃反应仍属未知。本文首次报道四(三苯基膦)合钯(O)催化氟烷基碘对烯烃的加成反应。     

氟烷基化和氟烷氧基化的研究 31. cd型阴服离子存在下烯烃的氟烷基化反应

氟烷基碘在cd型阴离子存在下能与烯烃加成, 得含氟烯烃, 反应能被光加速和被对二硝基苯部分阻止, 是一个单电子转移过程。     

氟烷基化和氟烷氧基化的研究 31. cd型阴服离子存在下烯烃的氟烷基化反应

氟烷基碘在cd型阴离子存在下能与烯烃加成, 得含氟烯烃, 反应能被光加速和被对二硝基苯部分阻止, 是一个单电子转移过程。     

氟烷基化和氟烷基化的研究 4.铜引发氟烷基碘对乙烯基三甲基硅烷的加长及其立体专一性合成相应的烯烃

在催化量的铜存在下,氟烷基碘R~FI(1)与乙烯基三甲基硅烷(2)在乙腈中反应生成高产率的氟烷基化产物3,二碘化物I(CF~2)~nI(4)也能与2反应生成单烷基化产物5和双烷基化产物6, 5和6量的相对比例取决于所用2的量,这类反应能被对苯二酚阻止;被对二硝基苯部分阻止,碘苯未能捕获到氟烷基铜中间体。表明反应可能是单电子转移引发的自由基链式机理.3与二乙胺反应得高产率的反式氟烷基三甲基硅乙烯7. 3与氢氧化钾在乙醇中反应得到的是7及其顺式异构体的混合物,将混合物用少量的溴处理可得纯的反式烯烃。     

氟烷基化和氟烷氧基化的研究 4.铜引发氟烷基碘对乙烯基三甲基硅烷的加成及其立体专一性合成相应的烯烃

在催化量的铜存在下,氟烷基碘R_FI(1)与乙烯基三甲基硅烷(2)在乙腈中反应生成高产率的氟烷基化产物8,二碘化物I(CF_2)_nI(4)也能与2反应生成单烷基化产物5和双烷基化产物6,5和6量的相对比例取决于所用2的量.这类反应能被对苯二酚阻止:被对二硝基苯部分阻止,碘苯未能捕获到氟烷基铜中间体.表明反应可能是单电子转移引发的自由基链式机理.3与二乙胺反应得高产率的反式氟烷基三甲基硅乙烯7.3与氢氧化钾在乙醇中反应得到的是7及其顺式异构体的混合物,将混合物用少量的溴处理可得纯的反式烯烃.     

氟烷基化和氟烷氧基化的研究9.氟烷基碘在铂(0)催化下对烯烃的加成反应

前已报道金属铜在乙酐,二乙二醇二甲醚或乙腈中通过单电子转移引发的氟烷基碘与烯烃或炔烃进行反应。最近,发现钯(0)在温和的条件下可催化氟烷基碘与烯烃的加成反应,产率甚佳。本文首次报道氟烷基碘在铂(0)络合物催化下与烯烃的加成反应。氟烷基碘与烯烃只需催化量(1～2mol%)的四(三苯基膦)合铂(0)就可在室温下进行加成反应,产率较高。     

氟烷基化和氟烷氧基化的研究 23: 锌单电子转移引发全氟烷基碘与吡咯的反应

在二甲亚砜或二甲基甲酰胺中, 锌能迅速引发全氟烷基碘(1)与吡咯的反应, 生成2-氟烷基吡咯(3); 在二氧六环中, 主要生成全氟烷基碘的偶合产物5; 在乙腈、二乙二醇二甲醚或苯等溶剂中, 则同时生成3和5, 反应能被二硝基苯阻止. 加入二烯丙基醚能得到氟烷基取代的四氢呋喃衍生物. 反应可能经锌单电子转移引发的自由基机理. 对溶剂效应作了讨论.     

1,3-二碘六氟丙烷的电子转移反应

在四醋酸铅的催化下,二氟二碘甲烷(CF2I2,1)与四氟乙烯加成生成1,3-二碘六氟丙烷(ICF2CF2CF2I,3).3与烯烃、炔烃和丙二酸二乙酯阴离子发生电子转移反应。     

三甲基硅氧基钠参与下的氟烷基碘与烯烃反应

近年来,氟烷基碘(1)对烯烃的加成反应得到了广泛的研究。我们已经报道了铜、锌、镁、铁、镍、钯、铂、铱等金属催化下的反应,以及cd型阴离子引发下的加成反     

Study on fluoroalkylation and fluoroalkoxylation: 19. Iridium(I)-catalyzed reaction of fluoroalkyl iodides with alkenes and alkynes

Fluoroalkyl iodides reacted with alkenes in the presence of hydridocarbonyltris(triphenylphosphine)iridium (I) to give the corresponding adducts in excellent yields under the mild conditions. Fluoroalkyl iodides reacted also with alkynes to afford E isomer of adducts predominantly. Addition of free radical inhibitor or single electron transfer scavenger to the reaction mixture partially suppressed the reaction. Diallyl ether could trap the fluoroalkyl radical to afford tetrahydrofuran derivative. XPS showed that the valence of Ir (I) rised at the end of the reaction. All findings seem to indicate that the reaction involves a free radical chain mechanism initiated by Ir (I).     

亚磺化脱卤研究 X: 全氟及多氟溴代烷的反应研究

本文报道溴代全氟烷和α,ω-二溴代全氟烷在亚磺化脱卤反应体系中与烯烃的反应及其与相应的碘代全氟烷的区别. 合成了全氟仲溴代烷CF3CFBrOCF2CF(CF3)O(CF2)2SO2F(7), 它与烯烃反应可得到1:1的加成物. 7的水解产物CF3CFBrOCF2CF(CF3)O(CF2)2SO3Na(11)与连二亚硫酸钠反应只得到氢化脱溴产物. 多氟溴化物CF3CBr2X(13X=F; 14X=Cl; 15X=Br)经亚磺化脱溴可得到相应的亚磺酸钠盐CF3CBrXSO2Na(16X=F; 17X=Cl; 18X=Br), 其中间体多氟烷自由基可用烯烃捕集, 得到高产率的1:1加成产物.     

全氟卤代烷在氯磺酸中的电化学反应

本文报道了以氯磺酸钾为电解质, 铂为电极, 进行氯磺酸的阳极氧化, 产生过氧二磺酰氯, 并和阳极池内α,ω-氯磺含氟烷进行反应, 生成相应的氯磺酸酯, 反应主要副产物为α,ω-二氯全氟烷, 在阳极有大量氢气逸出, 并得到碘。     

Linear metal-metal-bonded tetranuclear M-Mo-Mo-M complexes (M = Ir and Rh): oxidative metal-metal bond formation in a tetrametallic system and 1,4-addition reaction of alkyl halides

Reaction of Mo2(pyphos)4 (1) with [MCl(CO)2]2 (M = Ir and Rh) afforded linear tetranuclear complexes of a formula Mo2M2(CO)2(Cl)2(pyphos)4 (2, M = Ir; 3, M = Rh). X-ray diffraction studies confirmed that two "MCl(CO)" fragments are introduced into both axial sites of the Mo2 core in 1 and coordinated by two PPh2 groups in a trans fashion, thereby forming a square-planar geometry around each M(I) metal. Treatment of 2 and 3 with an excess amount of tBuNC and XylNC induced dissociation of the carbonyl and chloride ligands to yield the corresponding dicationic complexes [Mo2M2(pyphos)4(tBuNC)4](Cl)2 (5a, M = Ir; 6a, M = Rh) and [Mo2M2(pyphos)4(XylNC)4](Cl)2 (7, M = Ir; 8, M = Rh). Their molecular structures were characterized by spectroscopic data as well as X-ray diffraction studies of BPh4 derivatives [Mo2M2(pyphos)4(tBuNC)4](BPh4)2 (5b, M = Ir; 6c, M = Rh), which confirmed that there is no direct sigma-bonding interaction between the M(I) atom and the Mo2 core. The M(I) atom in 5 and 6 can be oxidized by either 2 equiv of [Cp2Fe][PF6] or an equimolar amount of I2 to afford Mo(II)2M(II)2 complexes, [Mo2M2(X)2(tBuNC)4(pyphos)4]2+ in which two Mo-M(II) single bonds are formed and the bond order of the Mo-Mo moiety has been decreased to three. The Ir(I) complex 5a reacted not only with methyl iodide but also with dichloromethane to afford the 1,4-oxidative addition products [Mo2Ir2(CH3)(I)(tBuNC)4(pyphos)4](Cl)2 (13) and [Mo2Ir2(CH2Cl)(Cl)(tBuNC)4(pyphos)4](Cl)2 (15), respectively, although the corresponding reactions using the Rh(I) analogue 6 did not proceed. Kinetic analysis of the reaction with CH3I suggested that the 1,4-oxidative addition to the Ir(I) complex occurs in an SN2 reaction mechanism.     

全氟烷基磺酰碘的化学

报导了全氟烷基亚磺酸银与碘之间在二氯甲烷中的低温反应(-30℃). 生成相应的全氟烷基磺酰碘. 并用^1^9F NMR证实其结构, 磺酰碘与各种稀烃反应则可产生二种系列的加成物RfSO2CH2CHIR和RfCH2CHIR.     

ω-氯氟烷基醇,烯烃及环氧化物的合成

全氟烷基碘的加成反应一直活跃在氟化学中,即使近来也依然受到注意,这是因为由它们出发可做许多有用的中间体,其中氟烷基取代的醇可做织物表面处理剂,氟烷基取代的环氧化合物可做润滑剂。我们曾用引发剂,使ψ—碘代全氟烷基磺酰氟与多键类化合物在较温和条件下进行加成。黄维垣教授等用NaHCO_3—K_3[Fe(CN)_6]引发Cl(CF_2)_(4.6)I与烯丙醇顺利加成。     

Environmentally benign processes for making useful fluorocarbons: nickel- or copper(I) iodide-catalyzed reaction of highly fluorinated epoxides with halogens in the absence of solvent and thermal addition of CF2I2 to olefins

Highly fluorinated epoxides react with halogens in the presence of nickel powder or CuI at elevated temperatures to provide a useful and general synthesis of dihalodifluoromethanes (CF(2)X(2)) and fluoroacyl fluorides (R(F)COF) in the absence of solvent. At 185 degrees C, hexafluoropropylene oxide and halogens produce CF(2)X(2) (X = I, Br) in 68-90% isolated yields, along with small amounts of X(CF(2))(n)()X, (n = 2, 3). With interhalogens I-X (X = Cl, Br), a mixture of CF(2)I(2), CF(2)XI, and CF(2)X(2) was obtained. The fluorinated epoxides substituted with perfluorophenyl, fluorosulfonyl, and chlorofluoroalkyl groups also react cleanly with iodine to give CF(2)I(2) and the corresponding fluorinated acyl fluorides in good yields. The reaction probably involves an oxidative addition of fluorinated epoxides into metal surfaces to form an oxametallacycle, followed by rapid decomposition to difluorocarbene-metal surfaces, which alters the reactivity of the difluorocarbene carbon from electrophilic to nucleophilic. The increase of nucleophilicity of difluorocarbene facilitates the reaction with electrophilic halogens. CF(2)I(2) reacted with olefins thermally to give 1,3-diiodofluoropropane derivatives. Both fluorinated and nonfluorinated alkenes gave good yields of the adducts. Reaction with ethylene, propylene, perfluoroalkylethylene, vinylidene fluoride, and trifluoroethylene provided the corresponding adducts in 58-86% yields. With tetrafluoroethylene, a 1:1 adduct was predominantly formed along with small amounts of higher homologues. In contrast to perfluoroalkyl iodides, CF(2)I(2) also readily adds to perfluorovinyl ethers to give 1,3-diiodoperfluoro ethers.     

Trifluoromethylthiolation of 1, 3- and 1, 4-Cyclohexadienes

Treatment of 1, 3-cyclohexadiene with CF 3 SCl at m 80°; furnishes 15 compounds. All but the two dimerized adducts arise from the free radical catalyzed addition of CF 3 S and Cl radicals to carbon-carbon double bonds. One dimerized product arises via dimerization of the substrate itself, while the other results from the cross-coupling of the substrate with the reaction product. The same reaction with 1, 4-cyclohexadiene gives 14 compounds. The mass spectral characterization of various compounds and their probable mechanism of formation are presented in this article.     

Synthesis and Structures of RhI and IrI Complexes Supported by N‐Heterocyclic Carbene‐Phosphinidene Adducts

N‐Heterocyclic carbene‐phosphinidene adducts of the type (IDipp)PR [R = Ph ( 5 ), SiMe₃ ( 6 ); IDipp = 1,3‐bis(2,6‐diisopropylphenyl)imidazolin‐2‐ylidene] were used as ligands for the preparation of rhodium(I) and iridium(I) complexes. Treatment of (IDipp)PPh ( 5 ) with the dimeric complexes [M(μ‐Cl)(COD)]₂ (M = Rh, Ir; COD = 1,5‐cyclcooctadiene) afforded the corresponding metal(I) complexes [M(COD)Cl{(IDipp)PPh}] [M = Rh ( 7 ) or Ir ( 8 )] in moderate to good yields. The reaction of (IDipp)PSiMe₃ ( 6 ) with [Ir(μ‐Cl)(COD)]₂ did not yield trimethylsilyl chloride elimination product, but furnished the 1:1 complex, [Ir(COD)Cl{(IDipp)PSiMe₃}] ( 9 ). Additionally, the rhodium‐COD complex 7 was converted into the corresponding rhodium‐carbonyl complex [Rh(CO)₂Cl{(IDipp)PPh}] ( 10 ) by reaction with an excess of carbon monoxide gas. All complexes were fully characterized by NMR spectroscopy, microanalyses, and single‐crystal X‐ray diffraction studies.