利用硅氢加成法高选择性合成甲基乙烯基二氯硅烷

利用硅氢加成法高选择性合成甲基乙烯基二氯硅烷兰支利李凤仪＊刘文明詹晓力（华南理工大学化工系广州５１０６４１）（南昌大学应用化学研究所３３００４７）硅氢加成法作为有机硅化合物的主要合成方法受到了人们的极大关注。乙炔的硅氢加成产物由于是带有乙烯基官能团的...     

负载型铂催化剂催化苯乙烯硅氢加成反应

分别研究了硅胶、γ-Al2O3和5分子筛负载聚乙二醇络合铂催化剂催化苯乙烯与甲基二氯硅烷的硅氢加成反应,发现这三种催化剂对β-加成产物的选择性为100%,不生成α-加成产物。而用Speier催化剂对β-加成产物的选择性为55%,产生α-加成产物。在这三种催化剂中,分子筛作载体的催化剂重复使用性较差,Al2O3作载体的催化剂诱导期较长,而硅胶作载体的催化剂比其它两种催化剂重复使用性好,且诱导期也较短,因此具有明显的优越性。文中还初步探讨了这三种催化剂出现高选择性的原因。     

乙炔和三乙氧基硅烷的硅氢加成反应研究

制备了氯铂酸-异丙醇、氯铂酸-聚甲基乙烯基硅氧烷和氯铂酸-三苯基膦三种催化剂,评价了它们在乙炔与三乙氧基硅烷的硅氢加成反应中的催化活性及选择性;并考察了反应温度、乙炔流量、氯铂酸-聚甲基乙烯基硅氧烷与三乙氧基硅烷摩尔比、PPh3/H2PtCl6摩尔比等因素对产物收率的影响.结果表明,氯铂酸-聚甲基乙烯基硅氧烷对该反应表现出较高的催化活性,在催化剂与三乙氧基硅烷摩尔比为1.2×10-4∶1,T=80℃,乙炔流量=120 mL/min的条件下反应,产物乙烯基三乙氧基硅烷的选择性为100%,收率可达97.5%.     

Pt(DVDS)-Phan催化的末端炔烃的硅氢加成反应

以Pt(DVDS)-Phan体系作为末端炔烃与三乙基硅烷或三苯基硅烷进行硅氢加成的催化剂, 除三甲基硅乙炔与三乙己硅烷反应外, 其余反应的收率均高于90%, 并且高选择性地或唯一地得到马氏加成产物或者反马氏反式加成产物, 立体选择性或区域选择性超过95%.     

C60乙二胺衍生物铂配合物的合成及其催化硅氢化性能

C₆₀与乙二胺反应,再与氯亚铂酸钾配位,得到了一种以C₆₀衍生物为基的Pt(Ⅱ)配合物,并研究了其在烯烃与三乙氧基硅烷的硅氢加成反应中的催化性能。结果表明,该配合物为硅氢加成反应的高效催化剂,并对苯乙烯有独特的催化性能,以近100%的区域选择性得到α-加成产物。     

4,4′-二（4-氯甲酰苯氧基）二苯砜的合成

以DMF作溶剂,在四丁基氟化铵 （TBAF）存在下,对甲基苯基三甲硅基醚（1）和4,4＇-二氯二苯砜（2）于100 ℃反应1 h,合成了4,4＇-二（4-甲基苯氧基）二苯砜（3）,产率为92%;加入催化量的N-溴代丁二酰亚胺（NBS）并在光照条件下,与氧气反应得到中间体-4,4＇-二（4-羧基苯氧基）二苯砜（4）,其产率达90%;将化合物4与二氯亚砜反应合成目标产物4,4＇-二（4-氯甲酰基苯氧基）二苯砜（5）,总收率为74.5%（以对甲基苯基三甲硅基醚为基准计算）.     

甲基环己基二氯硅烷合成工艺的研究

研究了在常压和无光照的情况下由环己烯和甲基二氯硅烷合成甲基环己基二氯硅烷的工艺，着重研究了合适的催化剂和助催化剂对氢硅加成反应的影响，并就反应液温度和反应时问对反应产物的影响进行色谱跟踪，研究显示反应过程可由反应液温度或反应时间来控制。该过程生产设备简单、操作简便、收率高。     

RANEY©Ni催化三乙酸内酯氢转移反应的研究

基于氢转移原理,以醇为氢源,将RANEY~? Ni催化剂用于三乙酸内脂(TAL)的加氢反应.通过筛选醇溶剂等条件,在氮气气氛中,以异丙醇为氢源,50℃下反应10 h可高选择性地制得89%的4-羟基-6-甲基四氢-2-吡喃酮.循环稳定性实验和氨基酸毒化实验证实RANEY~? Ni催化剂在该反应中优异的稳定性.     

羰基化合物的直接还原氯代反应

在甲基二氯氢硅烷存在下,FeCl3催化羰基化合物(1)的还原氯代反应,合成了氯代烷烃(2)。较适宜的反应条件为:11.00 mmol,甲基二氯氢硅烷1.10 mmol,FeCl30.05 mmol,乙二醇二甲醚20 mL,回流反应3 h~12 h。在该反应条件下,1均可直接转化为2,收率65%~95%。     

二苯基膦功能化氧化石墨固载铂催化剂的制备及其催化烯烃硅氢加成性能

以氧化石墨为载体,采用二苯基膦配体对其进行改性,再利用膦配体对Pt的螯合配位作用合成了氧化石墨固载膦铂配合物催化剂(GO-P-Pt),并采用元素分析、FT-IR、XRD等方法对催化剂进行了表征,考察了催化剂催化不同烯烃与三乙氧基硅烷的硅氢加成反应性能。结果表明,该催化剂对烯烃与三乙氧基硅烷的硅氢加成反应具有良好的催化活性,在100℃,反应180min后,1-辛烯的转化率为94.6%,β-加成产物的选择性高达99.4%;当底物为芳香烯烃时,β-加成产物的选择性比脂肪烯烃低。此外,催化剂在重复使用4次之后,活性基本保持不变。     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.