SYNTHESIS OF POLYBINAPHTHYLS INCORPORATING CHIRAL （R）-1,1′-BI-2,2′-NAPHTHOL ENTITIES WITH p-DIVINYLBENZENE BY Pd-CATALYZED HECK REACTION

Polymer (Ⅰ) and polymer (Ⅱ) were obtained by the polymerization of (R)-6,6′-dibromo-2,2′-binaphtho-20-crown-6 (M-l) and (R)-6,6′-dibromo-2,2′-di(methoxyethoxymethyloxy)-1,1′-binaphthyl (M-2) with p-divinylbenzene under Pdcatalyzed Heck reaction. The UV, fluorescence and CD spectra of polymer (Ⅰ) and (Ⅱ) are similar due to the same linkers present in their polymer chain. Polymers (Ⅰ) and (Ⅱ) can emit strong blue fluorescence and are expected to have potential applications in polarized blue-light emitting sensors. The chiral conjugated polymers (Ⅰ) and (Ⅱ) exhibit a strong Cotton effect in their circular dichroism (CD) spectra, indicating a high rigidity of polymer backbone.     

SYNTHESIS OF POLYBINAPHTHYLS INCORPORATING CHIRAL(R)-1,1''''-BI-2,2''''-NAPHTHOL ENTITIES WITH p-DIVINYLBENZENE BY Pd-CATALYZED HECK REACTION

INTRODUCTION(R) or (S) 2,2'-binaphthnol (BINOL) have often been used as the starting materials for obtaining chiral binaphthylcompounds. The 2,2'-hydroxyl groups of BINOL can be easily converted into other functional groups and the3,3'-and 6,6'-positions of naphthyl skeletal structure of BINOL can be selectively functionalized, leading to avariety of binaphthyl derivatives which can exhibit remarkably stable chiral configuration as well as high chiralinduction in many asymmetric proc…     

SYNTHESIS OF CHIRAL CONJUGATED POLYBINAPHTHYLS BY SONOGASHIRA REACTION

Chiral polymers P-1 and P-2 were synthesized by the polymerization of （R）-3,3＇-diiodo-2,2＇-bisbutoxy-1,1＇- binaphthyl （M- 1 ） with 2,5-di（4-ethynylphenyl）- 1,3,4-oxadiazole （M-3） and （R）-3,3＇-diethylnyl-2,2＇-bisbutoxy- 1,1 ＇-binaphthyl （M-2） with 1,2-di（4-bromophenyl）acetylene （M-4） under Sonogashira reaction, respectively. Both monomers and polymers were analyzed by NMR, MS, FT-IR, UV-Vis spectroscopy, DSC-TGA, fluorescence spectroscopy, GPC and CD spectroscopy. CD spectra of P-1 and P-2 are similar due to the same chiral center units and main chain structure. The long wavelengths CD effect of P-1 and P-2 can be regarded as the more extended conjugated structure and a highly rigid backbone in the polymer chain. Polymers have strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the polymers to the chiral binaphthyl core and are expected to provide understanding of the relationship between molecular structure and fluorescent property of the chiral polymers.     

POLYBINAPHTHYLS INCORPORATING (R)-2,2''''-BINAPHTHO-20-CROWN-6 AND NAPHTHYL MOITIES

Chiral polymer was synthesized by the polymerization of (R)-6,6'-bistributylstannyl-2,2'-binaphtho-20-crown-6 (M-1) with 1,4-dibromo-2,3-bisbutoxy-naphthyl (M-2) by Pd(PPh3)4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution of racemic amino acid.     

POLYBINAPHTHYLS INCORPORATING (R)-2,2’-BINAPHTHO-20-CROWN-6 AND NAPHTHYL MOITIES

Chiral polymer was synthesized by the polymerization of （R）-6,6＇-bistributylstannyl-2,2＇-binaphtho-20-crown-6 （M-1） with 1,4-dibromo-2,3-bisbutoxy-naphthyl （M-2） by Pd（PPhs）4 catalyzed Stille coupling reaction. Both monomer and polymer were analyzed by NMR, MS, FT-IR, UV, polarimetry, DSC-TGA, CD, fluorescent spectroscopy and GPC. The major difference between monomer and polymer is that a long wavelength Cotton Effect was observed for the polymer due to its more extended conjugation in the repeating unit and a highly rigid backbone in the polymer chain. Polymer has strong blue fluorescence due to the efficient energy migration from the extended n-electronic structure of the repeating unit of the polymer to the chiral binaphthyl core and is expected to have potential application in the materials of fluorescent sensors and chiral chromatographic packing for resolution ofracemic amino acid.     

SYNTHESIS OF THE CHIRAL α,β-UNSATURATED N-ACYL-OXAZOLIDIN-2-ONES BY WITTIG REACTION

A new, universal, and versatile method has been developed for the synthesis of the chiral α,β-unsaturated N-acyl-oxazolidin-2-ones 4 based on the Wittig reaction of the triphenylphosphonium salt 7 derived from the (R)-3-(2-Chloro-acetyl)-5,5-dimethyl-4-phenyl-oxazolidin-2-one 6.     

SYNTHESIS OF LATHANIDE PORPHYRIN BY SOLID STATE REACTION

ＳＹＮＴＨＥＳＩＳＯＦＬＡＴＨＡＮＩＤＥＰＯＲＰＨＹＲＩＮＢＹＳＯＬＩＤＳＴＡＴＥＲＥＡＣＴＩＯＮ￥ＧｕｏＦａＬＩＵａｎｄＴｏｎｇＳｈｕｎＳＨＩ（ＤｅｐａｒｔｍｅｎｔｏｆＣｈｅｍｉｓｔｒｙ，ＪｉｌｉｎＵｎｉｖｅｒｓｉｔｙ，Ｃｈａｎｇｃｈｕｎ，１３００...     

ASYMMETRIC SYNTHESIS——ENANTIOSELECTIVE SYNTHESIS OF (R)-α-AMINO ACIDS USING L-ISOLEUCINE AS CHIRAL AUXILIARY REAGENT

Enantioselective synthesis of (R)-α-amino acids via heterocyclic intermediate-(3S)-2,5-dimethoxy-3-see-butyl-3, 6-dihydropyrazine (5), using L-isoleucine as chiral auxiliaryreagent and glycine as raw meterial, has been studied. The alkylation of compound 5 withbutyllithium affords its lithium derivative (6) according to the cardanion mechanism. Then 6reacts with alkyl halide RX (7) to give the alkylated products (8) with very high diastereo-selectivity. In this reaction, the group R of 7 enters trans to the see-butyl group at C-3, i. e.the (R)-configuration is induced at C-6 of 8. After hydrolysis the (R)-α-amino acid methylesters (9) are obtained.     

Synthesis and applications of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene

The synthesis of (R)- and (S)-7,7′-dimethoxy-2,2′-bis(diphenylphosphino)-1,1′-binaphthalene 5a and 5b is described. The phosphorus atoms in (S)-(−)-5b are shown to be slightly more basic than the phosphorus atoms in (S)-BINAP by comparing the magnitude of the ¹J (³¹P–⁷⁷Se) coupling constant in their respective diselenide derivatives. (S)-(−)-5b behaved similarly to (S)-BINAP in asymmetric Heck reactions.     

AN EFFICIENT SYNTHESIS OF ω-(2,2′-BIPYRIDYL)ALKYL ALCOHOLS AND THEIR ACRYLATES

ABSTRACT

ω-(2,2′-Bipyridyl)alkyl alcohols were synthesized by treatment of methyl-2,2′-bipyridine with LDA at ?78°C followed by the addition of ω-bromoalkyl THP ether and hydrolysis of the resulting THP ether. Furthermore, ω-2,2′-bipyridylalkyl acrylates were obtained by the reaction of the corresponding ω-(2,2′-bipyridyl)alkyl alcohols with acryloyl chloride in good yields.     

A CONVENIENT SYNTHESIS OF 4-SUBSTITUTED-4′-(2-THIENYL)- 2,2′-BITHIAZOLES AS POTENTIAL PHOTOTOXIC AGENTS

Alpha-tosyloxyacetylthiophene (3), obtained by the hypervalent iodine oxidation of 2-acetylthiophene (2) using [hydroxy- (tosyloxy)iodo]benzene (HTIB), on treatment with rubeanic acid exclusively generates 4-(2-thienyl)thiazole-2-thiocarboxamide (4) which upon subsequent treatment with a variety of alpha-tosyloxyketones (5) affords the title compounds (6) in excellent yields.     

Optical Rotatory Feature of (R or S)-1,1′-Binaphthalene-2,2′-diol (BINOL) in Various Solvents

IntroductionElieletal.1,2 haveeverreportedthatsolventtypeandconcentrationwouldaffecttheequilibriumofcis 3 hydrox ythiane S oxideconformationwhichwascausedbyintermolec ularandintramolecularhydrogenbondformedwiththeinter actionbetweenthesolute solventandthesolute soluteinthesolutionandhaveimportantinfluenceonitsspecificrotation .Uptonowitisnotveryclear,however,whetherhydrogenbondingaffectsspecificrotation (inmagnitudeandoccasion allyinsign)directlyorwhetheritdoessoindirectly (byaf fectingconform…     

ULTRASOUND PROMOTED SYNTHESIS OF β-HYDROXYESTERS BY REFORMATSKY REACTION USING INDIUM METAL

Ultrasound promoted Reformatsky reaction by the reaction of aldehydes or ketone with ethyl bromoacetate in the presence of indium metal afforded β-hydroxyesters in good to excellent yields under mild conditions.     

SYNTHESIS OF 1-(ACETYLSALICYLYL)-BENZOTRIAZOLE AND ITS REACTION WITH POLYVINYL ALCOHOL

l-(Acetylsalicylyl)-benzotriazole, a new active amide of acetylsalicylic acid has been synthesized either from acetylsalicylic acid and benzotriazole using DCCI as condensation agent or via acetylsalicylyl chloride and benzotriazole in the presence of triethylamine. The obtained active amide reacted readily with the hydroxyl group of PVA to produce the acetylsalicylyl ester of PVA.     

NATURAL PRODUCTS SYNTHESIS BY RETRO-DIELS-ALDER REACTION Ⅷ~1 A CONCISE STEREOSPECIFIC FORMAL SYNTHESIS OF TETRAHYDROCHLOROVULONE

A potent antineoplastic tetrahydrochlorovulone 3 was synthesized with retro-Diels Alder reaction as a key step.     

SYNTHESIS OF 5α-(17R,20R)-14,15-SECOCHOLESTANE

The synthesis of 5α-(17R,20R)-14,15-secocholestane fromcholesterol was reported.     

SYNTHESIS AND ELECTRONIC SPECTRA OF RUTNENIUM(Ⅱ)-1,1''''-BIISOQUINOLINE COMPLEXES

l,l'-biisoquinoline can coordinate with ruthenfum(Ⅱ) to form a new series of mononuclear complexes and the electronic absorption of these complexes were measured and reasonably assigned.     

SYNTHESIS AND CHARACTERIZATION OF POLY(PHTHALAZINONE ETHER PHOSPHINE OXIDE)S BY N―C COUPLING REACTION

<正>Based on several unsymmetrical,twist,noncoplanar phthalazinone-containing monomers 2a-2e and an active bis(4-fluorophenyl)phenyl phosphine oxide(BFPPO) monomer,a series of novel poly(phthalazinone ether phosphine oxide)s (PPEPO) was synthesized by anhydrous K_2CO_3 mediated N—C coupling reaction in DMAc.The polymers exhibited good thermal properties with T_gs ranging from 267℃to 306℃and 5%weight loss temperatures in nitrogen higher than 430℃, together with high char yield upon prolonged heating at 800℃(35%—56%).Moreover,the polymers were readily soluble in common organic solvents,such as N-methyl-2-pyrrolidone,chloroform and m-cresol.These polymers had inherent viscosities in the range of 0.45-0.72 dL/g and could be cast into flexible and colorless films by spin coating or casting approach.     

NATURAL PRODUCTS SYNTHESIS BY RETRO-DIELS-ALDER REACTION Ⅱ~1 ASYMMETRIC SYNTHESIS OF (+) AND (-) 5-OXO-ENDO-TRICYCLO [5.2.1.0.~(2, 6)] DECA-3, 8-DIENE 1 BY ENZYME-CATALYZED REACTION

Asymmetric syntheses of both enantiomerically pure (+) and (-) 5-oxo-endo-tricyclo [5.2.1.0.~(2,6)] deca-3, 8-diene 1 was described. The key step is the use of enzyme-catalyzed hydrolysis of meso-diacetate 5.     

ENE REACTION WITH PUMMERER-TYPE REACTION INTERMEDIATE OF α-(METHYLTHIO)ACETIC ACID PYRROLIDIDE:SYNTHESIS OF ACHILLEA AMIDE AND TRICHONINE

The dienamide group is an important structural feature of a number of natural products, which have been reported to be biologically active, especially as insecticides. Several methods for their synthesis have appeared involving Wittig reaction, elimination reaction, and amidation of corresponding dienoic acids or esters. Achillea amide [(E,E)-2,4-tetradecadienoic acid pyrrolidide] and Trichonine [(E,E)-2,4-eicosadienoic acid pyrrolidide)] which are naturally occurring insecticides isolated from Achillea nana and P. trichostachyon leaves, respectively. Severál methods have reported successful syntheses of unsaturated pyrrolidine amides. In this work we wish to report that the Pummerer-type reaction intermediate 2 derived from α-(methylthio)acetic acid pyrrolidide (1) and phenyliodine(Ⅲ) bis(trifluoroacetate) (PIFA) undergoes an ene reaction with 1-alkenes to give the ene adducts 3. Also reported is its application to the synthesis of Achillea amide (4) and Trichonine (5).