对甲苯磺酸吡啶盐催化乙酸烯丙酯的烷氧基取代/重排反应

以对甲苯磺酸吡啶盐为催化剂,实现了乙酸烯丙酯的烷氧基取代/重排反应,收率60%～95%.产物的结构经1H NMR表征.     

烯胺酮与烯胺酯的交叉缩合反应

在三氟乙酸(TFA)作用下,烯胺酮(1)与烯胺酯(7或2)的[3C十3C]交叉缩合反应,主要形成2-胺基-4,6-二甲基苯甲酸甲酯(5)。讨论了三氟乙酸用最及不同的烯胺酮对[3C+3C]缩合反应中3的收率和产物分配的影响。烯胺酮在三氟乙酸作用下,可在温和的条件下自缩合,产物易于纯化。     

巯基/(甲基)丙烯酸(甲基)烯丙酯光固化特性

通过对羧酸盐法改进后合成同时含有高活性的丙烯酸酯型C=C和低自由基活性的烯丙基型C=C的烯类单体(甲基)丙烯酸(甲基)烯丙酯,以实现(甲基)丙烯酸酯类紫外光固化与巯/烯光聚合结合在二元体系中;并以1173为光引发剂,利用实时红外(RT-IR)跟踪此类烯烃与三羟甲基丙烷三(3-巯基丙酸酯)(TMMP)光固化过程,探究烯烃结构、光强和引发剂用量对含有两类碳碳双键的烯类单体与巯基化合物二元体系的光固化行为的影响.研究发现,这类二元巯-烯光聚合反应中均有(甲基)丙烯酸酯双键的反应活性最大,(甲基)烯丙基次之,巯基的反应活性最小;甲基取代在烯烃的不同C=C上,对巯-烯光固化特性影响不同,甲基取代在烯丙基C=C上比甲基取代在丙烯酸基C=C上对巯-烯光固化行为影响更大;巯基最终转化率随甲基取代基数目增多而减少;丙烯酸甲基烯丙酯体系中两类双键(丙烯酸型/甲基烯丙基型)反应活性几乎相同且均具有高的转化率.     

丙烯酰乙二胺盐酸盐的合成

丙烯酰氯与Boc单保护的乙二胺反应,合成了功能单体--丙烯酰乙二胺盐酸盐,总收率65%,其结构经1H NMR和IR表征.     

苯基碳酸烯丙酯类化合物的合成及其在手性仲胺拆分中的应用

以酚类化合物和氯化烯丙基甲酯为原料,合成了三种苯基碳酸烯丙酯化合物[1a～1c,其中2-甲氧基苯基碳酸烯丙酯(1b)为新化合物]。以1a～1c为酰基供体,在甲苯中经Novozyme 435酶催化对消旋的1-甲基-6,7-二甲氧基四氢异喹啉(2)进行拆分,得到手性仲胺S-2和R-2,转化率近50%,R-2的对映选择性>99%,其结构经1H NMR和13C NMR表征。     

硫酸氢钠催化合成羧酸烯丙酯

硫酸氢钠能够代替硫酸作为酯化催化剂。利用－水硫酸氢钠催化合成了甲酸烯丙酯、乙酸烯丙酯、丙酸烯丙酯、丁酸烯丙酯和戊酸烯丙酯,产物用折射率、元素分析和红外光谱表征。研究了硫酸氢钠用量对丙酸烯丙酯收率的影响。     

Fe(0)催化三氯乙酸烯丙酯的环化反应研究

通过对Fe(O)催化烯烃自由基环化反应的研究，发现以Fe(O)为催化剂催化三氯 乙酸烯丙酯分子内自由基环化反应可以高化学选择性得到五元环内酯产物，反应中 不需加入配体。和大多数自由基反应一样，反应温度与催化剂用量对该反应的转化 率和产率有着很大的影响。     

膦腈碱催化甲基丙烯酸烯丙酯与甲基丙烯酸甲酯的负离子共聚反应

室温下以膦腈碱(t-Bu P4)为催化剂,催化甲基丙烯酸烯丙酯(AMA)和甲基丙烯酸甲酯(MMA)进行负离子共聚反应.用核磁(1H-NMR、13C-NMR)、红外光谱(FTIR)、凝胶渗透色谱(GPC)、示差扫描量热仪(DSC)和热失重分析仪(TGA)等对聚合物结构和性能进行表征.结果发现,t-Bu P4能在室温下成功催化AMA与MMA的共聚反应,一步法合成结构可控的含悬垂双键共聚物.共聚反应中单体AMA和MMA的转化率均高于90%,且无交联或凝胶生成.通过NMR和FTIR对聚合物进行结构分析表明,AMA单体仅甲基丙烯酸酯双键参与聚合反应,烯丙基双键不参与聚合反应、无交联反应、环化反应等.聚合物中烯丙基结构单元的含量可通过体系中AMA/MMA的投料比调节.GPC结果表明所得共聚物分子量可控且分子量分布较窄.TGA和DSC结果表明,共聚物的热分解温度升高,玻璃化温度降低.     

烯虫酯的立体选择性全合成

以香茅醛为起始原料, 通过羟醛缩合反应和Reformatskii反应得到3,7,11-三甲基-2,4,10-十二碳三烯酸异丙酯的双键顺反异构体混合物, 经苯硫酚两次催化双键顺反异构化, (2E,4E)-异构体3a的含量由原来的26%提高到85%. 再通过醚化反应, 立体选择性地全合成了具有保幼激素活性的昆虫生长调节剂烯虫酯及其异构体, 即11-甲氧基-3,7,11-三甲基-2,4-十二碳二烯酸异丙酯. 其中具有较高生物活性的(2E,4E)-异构体的含量达85%. 各步所合成的化合物的结构经IR, MS和NMR证实.     

烯胺酮与烯胺酯的交叉缩合反应及自缩合反应的区域选择性研究

烯胺酮与烯胺酯以(3C+3C)缩合反应形成多取代芳环化合物,具有区域选择性。用波谱和 X-射线衍射技术确定了产物的结构,讨论了反应机理。     

Radical polymerization of allyl alcohol and allyl acetate

Monoallyl compounds are not readily homopolymerized by a conventional free‐radical mechanism. However, the polymerization of allylbiguanide hydrochloride was reported to proceed in a concentrated solution of hydrochloric or phosphoric acid in the presence of a radical initiator. Here we have studied the polymerization of allyl alcohol by a radical initiator in the presence of a Lewis acid (ZnCl₂, CuCl₂ or MgCl₂) in an organic solvent (toluene, hexane, methanol or isopropanol). Reactions were performed either at room temperature or 50°C under an atmosphere of nitrogen or in a sealed tube. The same polymerization was also carried out in water and in a concentrated acid solution. The polymer product was purified by dialysis in 0.2–3.7% yield and confirmed by elemental analysis, infrared spectroscopy and ¹H NMR. The molecular weight range of poly(allyl alcohol) was 10,000–35,000. The polymerization of allyl acetate by the radical initiator under the above conditions gave poly(allyl acetate) with the molecular weight range of 10,000–13,800 by multi‐angle laser light scattering. Copyright © 2007 John Wiley & Sons, Ltd.     

Linear polymers of allyl acrylate and allyl methacrylate

Allyl acrylate and allyl methacrylate were polymerized by anionic initiators to soluble linear polymers containing allyl groups in the pendant side chains. The pendant unpolymerized allyl groups of the resulting linear poly(allyl acrylates) were shown to be present by: (1) the disappearance of the acrylyl and methacrylyl double bond absorptions in the infrared spectra in the conversions of monomers to polymers; (2) postbromination of the allyl bonds in the linear polymer; (3) the disappearance of the allyl groups absorptions in the infrared spectra of the brominated linear polymers; and (4) the thermal- and radical-initiated crosslinking of the linear polymers through the allyl groups. Allyl acrylate and allyl methacrylate show great reluctance to copolymerize with styrene under anionic initiation, but copolymerize readily with methyl methacrylate and acrylonitrile. Block copolymers were prepared by reacting allyl methacrylate with preformed polystyrene and poly(methyl methacrylate) anions. The linear polymers and copolymers of allyl acrylate may be classified as “self-reactive” polymers which yield thermosetting polymers. Bromination of the linear polymers offers a convenient method of producing self-extinguishing polymers.     

Kinetics and mechanisms of the allyl + allyl and allyl + propargyl recombination reactions

The kinetics and mechanisms of the self-reaction of allyl radicals and the cross-reaction between allyl and propargyl radicals were studied both experimentally and theoretically. The experiments were carried out over the temperature range 295-800 K and the pressure range 20-200 Torr (maintained by He or N(2)). The allyl and propargyl radicals were generated by the pulsed laser photolysis of respective precursors, 1,5-hexadiene and propargyl chloride, and were probed by using a cavity ring-down spectroscopy technique. The temperature-dependent absorption cross sections of the radicals were measured relative to that of the HCO radical. The rate constants have been determined to be k(C(3)H(5) + C(3)H(5)) = 1.40 × 10(-8)T(-0.933) exp(-225/T) cm(3) molecule(-1) s(-1) (Δ log(10)k = ± 0.088) and k(C(3)H(5) + C(3)H(3)) = 1.71 × 10(-7)T(-1.182) exp(-255/T) cm(3) molecule(-1) s(-1) (Δ log(10)k = ± 0.069) with 2σ uncertainty limits. The potential energy surfaces for both reactions were calculated with the CBS-QB3 and CASPT2 quantum chemical methods, and the product channels have been investigated by the steady-state master equation analyses based on the Rice-Ramsperger-Kassel-Marcus theory. The results indicated that the reaction between allyl and propargyl radicals produces five-membered ring compounds in combustion conditions, while the formations of the cyclic species are unlikely in the self-reaction of allyl radicals. The temperature- and pressure-dependent rate constant expressions for the important reaction pathways are presented for kinetic modeling.     

Conformational study of allyl fluoride,allyl alcohol and allyl amine through the matrix-isolation technique

In a vibrational analysis of allyl compounds, which was made difficult because of autoassociation and conformational equilibrium, we have used the matr     

Catalyzed cross-coupling of allyl bromides with allyl tin reagents

The reaction of allyl bromides with allyl tin reagents, catalyzed by palladium or zinc chloride gives cross-coupled products without allylic transpostion in the allyl halide partner but with predominate allylic rearrangement from the tin partner.     

Gas-phase thermolysis of sulfur compounds. Part VIII. Chloromethyl allyl,cyanomethyl allyl, 1-cyanoethyl allyl and neopentyl allyl sulfides

The pyrolyses of four alkyl allyl sulfides with substituents on the α? C atom of the alkyl moiety have been studied in a stirred-flow system over the temperature range 340-400°C and pressures between 2 and 12 torr. The only products formed are propene and thioaldehydes. The reactions showed first-order kinetics with the rate coefficients following the Arrhenius equations: Chloromethyl allyl sulfide: Cyanomethyl allyl sulfide: 1-cyanoethyl allyl sulfide: Neopentyl allyl sulfide: The effects of these and other substituents on the reactivity is discussed in relation with the stabilization of a polar six-centered transition state. The results support a non-concerted mechanism where the 1–5 α? H atom shift is assisted by its acidic character.     

Gas-phase thermolysis of allyl propargyl amine,allyl cyanomethyl propargyl amine,allyl propargyl 2-thiapropyl amine,and allyl methanesulfonyl propargyl amine

The title amines have been pyrolyzed in a stirred-flow reactor, at temperatures of 360–500°C, pressures of 7–16 torr, and residence times of 0.5–2.9 s, using toluene as carrier gas. The reaction products were allene, propene, and the corresponding imines. The ratio allene:propene varied in the range 6.7–1.6. The amines with CH₂CN and SO₂CH₃ substituents also formed HCN and SO₂. These appear to arise from complex free radical decomposition of the imine product. The first-order rate coefficients for the production of allene plus propene followed the Arrhenius equations: Allyl propargl amine: Allyl cyanomethyl propargyl amine: Allyl propargyl 2-thiapropyl amine: Allyl methanesulfonyl propargyl amine: Nonconcerted mechanisms, involving polar six center cyclic transition states, are suggested for the elimination of allene and propene. © 1994 John Wiley & Sons, Inc.     

Conformations and vibrational spectra of allyl isocyanate and allyl isothiocyanate

The infrared spectra of allyl isocyanate and allyl isothiocyanate as vapours and liquids were recorded in the region 4000-50 cm^?1. Additional spectra of the amorphous and crystalline solids at ?180°C were recorded between 4000 and 400 cm^?1. p]Raman spectra, including semiquantitative polarization measurements were obtained of the liquids, and spectra of the unannealed as well as of the crystalline solids at ?180°C were recorded.A considerable simplification of the vibrational spectra of the crystals compared to the liquids was observed as a consequence of the conformational equilibria in these compounds. It can be concluded with confidence that a cis conformation of the allyl group was present in the crystals of both compounds with additional gauche conformers in the liquids. No definite conclusions can be reached regarding the conformational arrangement of the -NCX groups. A remarkable similarity was observed between the spectra of the two compounds, and all the fundamental frequencies except the lowest C-N torsion have been assigned for the cis conformers. More than ten fundamentals for the gauche conformers have also been assigned.     

Generation of allyl Grignard reagents via titanocene-catalyzed activation of allyl halides

A protocol for the generation of allyl Grignard reagents via the catalytic activation of allyl halides is described herein. Subsequent nucleophilic addition to carbonyl derivatives provided the desired homo allylic alcohols in excellent yields (84-99%). Evidence suggests that titanocene dichloride catalyzes the formation of an allyl Grignard species which reacts solely with the carbonyl electrophile as evidenced by the complete absence of Würtz coupling. This methodology will have wide-ranging applicability in the generation of highly reactive organometallic reagents.