Excess Volumes of Ternary Mixtures Containing N-Methylcyclohexylamine,Benzene with 1-Alkanols at 303.15 K

Abstract

New excess volume data have been measured for three ternary mixtures at 303.15 K. The mixtures included N-methylcyclohexylamine and benzene as common components. 1-propanol, 1-butanol and 1-pentanol were chosen as non-common components. The data were compared with those predicted by empirical relations. The experimental results have been analysed in terms of intermolecular interactions between unlike molecules.     

Highly Efficient Route to Functionalized Tetrahydrocarbazoles Using a Tandem Cross‐Metathesis/Intramolecular‐Hydroarylation Sequence

The scope of the novel ruthenium‐catalyzed tandem cross‐metathesis/intramolecular‐hydroarylation sequence is described. This methodology offers a practical and efficient synthesis of structurally diverse and complex tetrahydrocarbazoles in good to excellent yields (up to 98 %). Moreover, preliminary efforts towards the development of an enantioselective version of the current process by sequential catalysis with ruthenium complex and chiral amine are presented, with high yields and enantioselectivities (up to 88 % yield and 91 % ee).     

Catalytic behavior of wool‐osmium tetroxide complex for asymmetric dihydroxylation of olefins

A new chiral polymer‐metal complex, wool‐osmium tetroxide (wool‐OsO₄) complex was prepared by a very simple method. This complex was found to be able to catalyze the asymmetric dihydroxylation of allylamine to (R)‐(+)‐3‐amino‐1, 2‐propanediol and allyl chloride to (S)‐(+)‐3‐chloro‐1,2‐propanediol. The optical yields amounted to 83.7 and 57.2%, and the product yields were 80.2 and 68.5% respectively. The experimental results showed that OsO₄ content in the complex, reaction time, allylamine/OsO₄ molar ratio and solvent all have an effect on the product and optical yields. Additionally, wool‐OsO₄ complex catalyst could be reused without any remarkable change in optical catalytic activity. Copyright © 2004 John Wiley & Sons, Ltd.     

Catalytic enantioselective Diels-Alder reaction in ionic liquid via a recyclable chiral In(III) complex

[Structure: see text] A recyclable, air- and moisture-stable chiral indium complex in [hmim][PF6-] ionic liquid has been developed. The cycloaddition of a variety of cyclic and open-chained dienes to 2-methacrolein and 2-bromoacrolein resulted in good yields and excellent enantioselectivities (up to 98% ee). Moreover, the chiral In(III) complex can be reused for seven successive cycles with comparable enantioselectivities and yields without loss of catalytic activity.     

Chiral base-mediated benzylic functionalisation of tricarbonylchromium(0) complexes of benzylamine derivatives

The novel complex (eta 6-benzylamine)tricarbonylchromium(0) 11 was prepared in up to 66% yield by direct complexation with Cr(CO)6 in refluxing 1,4-dioxane. Imine derivatives of this complex were readily deprotonated at the benzylic position by diamide 5, and the resultant anions reacted regioselectively with electrophiles (Me3SiCl or MeI) to give fairly good yields of products substituted at the benzylic carbon. Products of up to 87% e.e. were obtained in these reactions, with the highest enantioselectivity being derived from the tert-butyl-substituted imine complex 25.     

基于配合共保护策略合成γ-L-谷氨酰二肽的新方法

提出了一种采用谷氨酸席夫碱Ni(II)配合物共保护L-谷氨酸的α-氨基和α-羧基合成γ-L-谷氨酰二肽的新方法. 首先由手性助剂——2-[N-(N-苄基-脯氨酰)氨基]二苯甲酮(1)、六水合氯化镍和L-谷氨酸反应, 得到谷氨酸席夫碱Ni(II)配合物2, 产率为98.2%; 进而采用二异丙基碳二亚胺(DIC)/1-羟基-苯并三唑(HOBt)复合缩合剂法分别与L-氨基酸3a～3h反应, 得到相应的γ-L-谷氨酰二肽席夫碱Ni(II)配合物4a～4h, 产率为93.1%～99.0%; 最后稀酸水解配合物, 得到γ-L-谷氨酰二肽5a～5h, 产率为73.0%～86.4%, 高收率(92.2%～97.4%)回收手性助剂. 中间产物和终产物的结构经由旋光, 1H NMR, 13C NMR和HRMS表征.     

Asymmetric hydrosilylation of ketones catalysed by a chiral rhodium complex

Synthesis of optically active alkoxysilanes by asymmetric hydrosilylation of ketones, in the presence of a chiral phosphine—rhodium complex, is described; optical yields up to 46% are observed.     

Synthesis of 3-indole derivatives by copper sulfonato Salen catalyzed three-component reactions in water

An efficient three-component reaction of indole, aldehyde, and malononitrile in water catalyzed by a copper(II) sulfonato Salen complex afforded 3-indole derivatives in good to excellent yields up to 97%.     

Enantioselective synthesis of alpha-aminopropargylphosphonates

α-Aminopropargylphosphonates have been synthesized for the first time in good yields and enantiomeric excesses (up to 81% ee) by using a copper(I)-pybox complex as the catalyst.     

新型四氮锰配合物催化烯烃环氧化反应的研究

合成了一种新型四氮配体(1,3-bis(pyridin-2-ylmethyl)imidazolidine)及其相应的锰(MnⅡ)配合物,并将其应用于催化过氧乙酸氧化烯烃的环氧化反应中,考察了催化剂当量及氧化剂当量等一系列条件对反应结果的影响,并在优化条件下研究了各种底物的适用范围,最终取得了很好的化学选择性及85％～9...     

Self-assembly of an organocatalyst for the enantioselective synthesis of Michael adducts and α-aminoxy alcohols in a nonpolar medium

A proline–thiourea host–guest complex is described as a self-assembled organocatalyst for the enantioselective Michael addition of aldehydes to nitroolefins and for the asymmetric α-aminoxylation of both aldehydes and ketones. The Michael adducts were obtained in good yields of up to 80%, high diastereoselectivities of up to 5:95, and high enantiomeric excesses of up to 98%. The optically active aminoxy alcohols were synthesized in 60–85% yields with 94–99% enantiomeric excesses after reduction of the α-oxidation products using NaBH₄.     

铜胺络合物作用下取代2-萘酚的交叉偶合反应

在铜(II)-胺络合物作用下, 取代2-萘酚化合物进行交叉偶合反应, 得到几种结构新颖的取代1,1'-联-2-萘酚化合物, 产率44%～90%. 化合物的结构经过核磁、红外光谱及质谱进行确证.     

Highly enantioselective cyanosilylation of aldehydes catalyzed by novel beta-amino alcohol-titanium complexes

The beta-amino alcohol 1b-Ti(Oi-Pr)(4) complex has been shown to catalyze the enantioselective cyanosilylation of aldehydes efficiently. In the presence of 5 mol % of 1b-Ti(Oi-Pr)(4) complex catalyst, the aromatic, conjugated, heteroaromatic, and aliphatic aldehydes were converted to their corresponding trimethylsilyl ethers of cyanohydrins in 90-99% yields with up to 94% ee under mild conditions.     

Silica-Supported Phosphine Palladium(0) Complex Catalyzed Phenylation of Acid Chlorides and Aryl Iodides by Sodium Tetraphenylborate

In the presence of a catalytic amount of silica – supported phosphine palladium(0) complex, sodium tetraphenylborate (NaBPh₄) reacts with acid chlorides under mild conditions to give the corresponding phenyl ketones in 57 – 80% yields; it also reacts with aryl iodides to afford the corresponding biaryls in 75 – 84% yields.     

Catalytic enantioselective addition of dialkylzinc to N-diphenylphosphinoylimines. A practical synthesis of alpha-chiral amines

The enantioselective addition of dialkylzinc reagents to N-diphenylphosphinoylimines derived from aryl-, furyl-, and cyclopropylaldehydes is efficiently catalyzed by a copper(II) triflate/(R,R)-MeDUPHOS complex. The yields are high (51-98%), and the enantiomeric excesses vary from 85 to 96%. This route provides a practical route to alpha-chiral amines.     

Donor-Acceptor Complexes in Copolymerization. XVIII. Alternating Diene–Dienophile Copolymers. 1. Conjugated Diene–Maleic Anhydride Copolymers through Radical-Catalyzed Polymerization

The copolymerization of isoprene, butadiene, and other conjugated dienes with maleic anhydride was readily initiated in polar solvents by conventional free radical catalysts, including peroxides, hydroperoxides, and azobisisobutyronitrile, at high concentrations or at temperatures at which the catalyst had a half-life of 1 hr or less and the total reaction time was 0.5-1 hr. Decreasing the reaction temperature or the rate of catalyst addition resulted in increased yields of Diels-Alder adduct and decreased yields of copolymer. The molecular weight decreased as the temperature increased. Dioxane and tetrahydrofuran peroxides, obtained by the passage of oxygen or UV irradiation in air, also initiated the copolymerization. The soluble diene-maleic anhydride copolymers were equimolar and alternating, had [n] 0.1-6 (cyclohexanone) and contained 75-95% 1,4 structure according to ozonolysis, titration with IC1 and NMR. The IR spectrum of the butadiene–maleic anhydride copolymer indicated 75-95% cis-1,4, 5-20% trans-1,4 and 0-5% 1,2-vinyl unsaturation. The proposed mechanism of polymerization involves a donor-acceptor (diene-dienophile) interaction generating a ground-state charge transfer complex which is readily converted to the cyclic adduct. Under the influence of radicals the ground-state complex is transformed into an excited complex which undergoes polymerization. High concentrations of radicals are necessary to generate polymerizable excited complexes in competition with adduct formation.     

Enantioselective aza-Michael reaction of hydrazide to chalcones through the nonactivated amine moiety conjugated addition

The catalytic asymmetric aza-Michael reaction of benzoyl hydrazine toward chalcones through the nonactivated amine moiety conjugated addition was facilitated by the developed N,N'-dioxide-Sc(OTf)(3) complex under mild conditions, affording the pharmacologically and synthetically useful products in moderate to high yields with up to 97% ee.     

Iron-catalyzed ene-type propargylation of diarylethylenes with propargyl alcohols

The diarylalkenyl propargylic complex framework has been found in many natural products and medicinal regents. Herein, we have disclosed an unprecedented FeCl(3) catalyzed ene-type reaction of propargylic alcohols with 1,1-diaryl alkenes which enabled us to furnish a diarylalkenyl propargylic complex framework in moderate to high chemical yields (up to 98%).     

Catalytic asymmetric bromination and chlorination of beta-ketoesters

The first general catalytic asymmetric bromination and chlorination of beta-ketoesters has been developed. The reactions proceed for both acyclic and cyclic beta-ketoesters catalyzed by chiral bisoxazolinecopper(II) complexes giving the corresponding optically active alpha-bromo- and alpha-chloro-beta-ketoesters in high yields and moderate to good enantioselectivities. For the optically active chlorinated products the isolated yields are in the range of 88-99 % and the enantiomeric excesses up to 77 % ee, while the optically active brominated adducts are formed in 70-99 % isolated yield and up to 82 % ee. Based on the absolute configuration of the optically active products, the face selectivity for the catalytic enantioselective halogenation is discussed based on a bidentate coordination of the beta-ketoester to the chiral catalyst and a X-ray structure of chiral alpha,gamma-diketoesterenolatebisoxazolinecopper(II) complex.     

Chiral Aluminum Complex Controls Enantioselective Nickel-Catalyzed Synthesis of Indenes: C−CN Bond Activation

A chiral aluminum complex controlled, enantioselective nickel-catalyzed domino reaction of aryl nitriles and alkynes proceeding by C−CN bond activation was developed. The reaction provides various indenes, bearing chiral all-carbon quaternary centers, under mild reaction conditions in yields of 32 to 91 % and ee values within the 73–98 % range. The reaction mechanism and aspects of stereocontrol were investigated by DFT calculations.