(+)-(1S,2S,5R)-8-联苯薄荷醇的合成

以(R)-( )-pu legone为起始原料,经1,4-加成,还原两步反应合成了手性辅助试剂( )-(1S,2S,5R)-8-联苯薄荷醇及其差向异构体(-)-(1R,2S,5R)-8-联苯薄荷醇,总产率95%。其结构经1H NMR,13C NMR,IR,MS和X-射线衍射仪表征。     

Asymmetric Catalysis. Part 149 [1]. Synthesis of New Chiral Tridentate Ligands for Enantioselective Catalysis

Summary. The synthesis of new chiral tridentate ligands is reported which coordinate transition metals in a meridional way. The ligands contain a pyridine ring, an oxazoline ring, and a strongly coordinating diphenylphosphanyl group. The methionine-derived ligand forms a copper complex, which has been studied by X-ray crystallography. The new ligands were tested in models of enantioselective catalyses, such as hydrogenation of ketopantolactone, hydrosilylation of acetophenone, and transfer hydrogenation of acetophenone.X-ray structure analysesReceived March 4, 2003; accepted March 4, 2003 Published online August 18, 2003     

(1R,6R)-(+)-鱼腥藻毒素的合成

鱼腥藻毒素(Anatoxin-a)是自兰藻类水华鱼腥藻(Anabaena flos-aquae)中分离的一种氮杂双环胺类生物碱,其化学结构及绝对构型经X光晶体衍射法测定分析为:(1R,6R)(+)-2-乙酰基-9-氮双环[4.2.1]壬-2-烯,简称为AnTX-a。     

Synthesis of (+)-(R)-Tiruchanduramine

The absolute stereochemistry of the marine alkaloid (+)-(R)-tiruchanduramine was established via a convergent total synthesis in six steps and 15.5% overall yield from Fmoc-D-Dab(Boc)-OH.     

Dendrimer-Like Chiral Stationary Phases Derived from (1R, 2R)-(+)-1,2-Diphenylethylenediamine and 1,3,5-Benzenetricarbonyl Trichloride

Three dendrimers were synthesized directly on aminated silica gel using (1R, 2R)-(+)-1,2-diphenylethylenediamine and 1,3,5-benzenetricarbonyl trichloride as building blocks. The chiral stationary phases were obtained by modification of these dendrimers with phenyl isocyanate. All derivatives prepared on silica gel were characterized by FTIR spectrum, solid-state ¹H NMR and elemental analysis. The enantioseparation ability of the chiral stationary phases was preliminarily evaluated by high-performance liquid chromatography. The chiral stationary phase of one-generation dendrimer exhibited best enantioseparation ability.     

Stereoselective Synthesis and Complexation of a New Chiral Hybrid Phosphine-Phosphine Oxide Ligand from (S)-(+)-Prolinol

Abstract

The synthesis and the complex formation of chiral heterotopic ligands with two different binding sites each capable of bonding a different type of metal are described. The action of bis(dimethylamino) aryl phosphine on (S)-(+)-prolinol gives rise to the kinetic stereoisomer (2S,4S)-2-phenyl-1,3,2-oxazaphospholidine 1 and the thermodynamic stereoisomer (2R,4S)-2-phenyl-1,3,2-oxazaphospholidine 2. 1 is then totally converted into 2 at the end of the reaction. The Michaelis Arbuzov reaction of 2 with benzylbromide affords (R_p)-benzylaryl-(2-(S)-bromomethyl pyrrolidine-1-yl) phosphine oxide 3 in 80% yield. Compound 3 is an ideal chiral precursor for the synthesis of chiral hybrid phosphine-phosphine oxide ligands. The bromide atom is smoothly displaced by lithium diphenylphosphide to afford in 80% yield (R_p)-benzylaryl-(2-(S)-diphenylphosphinomethylpyrrolidine-1-yl) phosphine oxide 5. These reaction are proved to be totally stereoselective : the Michaelis Arbuzov reaction does not change the configuration at C2 in the proline ring. The relative configuration (R_p) of 5 (aryl = phenyl) was determinated by X-ray diffraction, from the known configuration of (S)-(+)-prolinol.     

一种新的手性三齿膦配体的合成及其应用

自从１９６６年第一个不对称催化反应［１］问世以来，研究最为广泛、深入的是不对称催化氢化反应．由于手性配体是手性催化剂产生不对称诱导和控制的源泉，因此，人们对手性配体研究得较为深入，已经出现了上千种不同结构的手性膦配体，其中手性双膦配体较多，而三齿膦配...     

Synthesis of New Chiral Bis(BINOL) Substituted 2,2''''-Bipyridine Ligands

Chiral 2,2'-bipyridines have been reported to be highly efficient catalysts and useful building blocks of supramolecular.[1,2] Chirality of bipyridines was introduced by chiral substituents. Because 1,1'-binaphthyl (BINOL) and its derivatives belong to the most important components of asymmetric catalysts, we would like to synthesize 5,5'-and 6,6'-positions substituted chiral bipyridine-type ligands, the chiral moieties of ligands originate from enationpure 1, 1'-binapthyl units.     

Synthesis of Enantiomerically Pure 1-(R)- and 1-(S)-Hydroxymethyl-Dtpa Penta-t-Butyl Esters Via Chiral Aminoalcohols

A convenient synthesis of enantiomerically enriched 1-hydroxymethyl-DTPA (diethylenetriamine pentaacetic acid) penta-t-butyl esters 3 has been achieved for the preparation of chiral synthones of new paramagnetic gadolinium complexes.     

Template Synthesis of Tin(IV) Complexes with Tridentate Iminopyridine Ligands

Russian Journal of Coordination Chemistry - Six-coordinate metal complexes containing tridentate Schiff  bases with an ONN-chelating moiety were prepared by template synthesis on tin...     

A Convenient Synthesis of (R)-(+)-Perillaldehyde

A short and efficient synthesis of the commercially unavailable (R)-(+) isomer of perillaldehyde from (+)-limonene oxide has been developed.     

Synthesis of Some New Chiral Sulfonamide Ligands

Synthesis of new chiral sulfonamide ligands derived from isatoic anhydride by reaction with trans-(R,R)-1,2-diaminocyclohexane and chiral aminoacid esters.     

新型手性氢化喹啉唑啉配体的合成

以8-喹啉羧酸为原料,通过8-喹啉酰氯与手性氨基醇反应或8-喹啉羧酸乙酯与氨基醇的酯交换反应制得酰胺6a-c,再经Ni-Al合金催化还原、甲磺酸催化脱水关环,合成了新型手性氢化喹啉唑啉配体2a-c.在苯乙酮的不对称催化氢转移反应的初步研究中,使用2C与RuCl2(Cymene)]2形成的手性催化剂得到71%产率和44%的e.e值.     

Synthesis of Chiral Ligands on the Basis of 1-(Adamantan-1-yl)ethane-1,2-diamine

Russian Journal of Organic Chemistry - The reduction of 1-(adamantan-1-yl)-2-azidoethan-1-one oxime with LiAlH4 gave racemic 1-(adamantan-1-yl)ethane-1,2-diamine, which was resolved with l-tartaric...     

The Total Synthesis of (±)-Camphor and (±)-Epicamphorenone from Methylcyclopentadiene

The total synthesis of (±)-carnphor and (±)-epicamphorenone from methylcyclopentadiene are described.