(1R,2R)-(+)-(1,2)-DPEN-Bonded Sulfonic Acid Resin: A Trifunctional Heterogeneous Catalyst for Asymmetric Michael Additions of Acetone to Nitroolefins

Based on (1R,2R)-(+)-(1,2)-DPEN skeleton, a series of primary amine–sulfamide bifunctional catalysts were synthesized, which exhibited excellent catalytic performance in the Michael addition of acetone to β-nitrostyrene. Therefore, a trifunctional heterogeneous catalyst was designed and prepared by simple N-sulfonyl reaction of (1R,2R)-(+)-(1,2)-DPEN and sulfonyl chloride resin. It was employed for the aforementioned addition without any additive and satisfactory results (80.5% conversion; 84.3% ee) were obtained. Meanwhile, the structural and textural properties of the catalyst were characterized by infrared spectroscopy (FT-IR), elemental analysis, SEM, and N₂ adsorption and desorption experiments. Finally, the generality of the catalyst was investigated.     

Asymmetric synthesis of (R)-(+)-etomoxir via enzymatic resolution

An asymmetric synthesis of (R)-(+)-etomoxir 3, employing enzymatic resolution of ethyl 2-alkyl-2,3-dihydroxypropionate using Amano AK via transacylation is reported.     

Efficient Synthesis of Ephedra Alkaloid Analogues Using an Enantiomerically Pure N-[(R)-(+)-alpha-Methylbenzyl]aziridine-2-carboxaldehyde

Efficient preparation of enantiomerically pure (2S)-aziridine-2-carboxaldehyde 9 and its 2(R) isomer and highly diastereoselective addition of organolithium reagents to the aldehyde 9 are described. The diastereoselectivity in additions of the lithium reagents seems to come from "chelation-controlled" carbon-carbon bond formation and is influenced by the source of the organometallic compound, solvent, and the presence of a Li salt. The C(3)-N bond of the aziridine ring of the addition products was regioselectively reduced by catalytic hydrogenation in the presence of Pearlman's catalyst to provide enantiomerically pure 1,2-amino alcohols. The absolute stereochemistries of the amino alcohol 13a were assigned as (1S,2S) when the C-1 substituent was phenyl by comparison with those of commercially available norpseudoephedrine.     

Highly stereoselective additions of sulfur stabilized carbanions to [(S)R]-2-(p-tolylsulfinyl)cyclohexanones

We describe the addition reactions of α-thiocarbanions derived from sulfoxides, thioethers, and sulfones to 2-(p-tolylsulfinyl)cyclohexanones. The high stereoselectivity observed in the formation of the chiral hydroxylic carbon is controlled by the configuration of the sulfinyl group at the substrate, but it is modulated by the nature of the sulfur function at the reagent (SOTol>SO₂Ph>SPh). The highly stereoselective formation of the second stereogenic center generated in these reactions from prochiral anions is only achieved with sulfinylcarbanions, the configuration of which controls that of such a center.     

用于烯烃二羟化反应的一种经济，高效且可重复使用的催化体系

以价廉的3,6-二氯哒嗪和奎宁为原料,通过两步反应即可得到一种可重复使用的金鸡纳生物碱衍生物配体。以NMO为辅助氧化剂在丙酮－水体系中，将此配体用于七种烯烃的不对称二羟化反应。反应结束后，用乙醚将产品从催化体系中萃取出来，得到80%~93%的产率和51%~99%的对映体过量值。以反式－二苯乙烯为底物进行催化体系的重复使用试验。循环使用十次，得到88%~92%的产率和>99%的对映体过量值。     

Asymmetric Synthesis and Crystal Structure of （-）-N-[（3R）-3-Cyclohexyl]-3-phenylpropananoyl]bornane-10,2-sultam

The title compound (-)-N-[(3R)-3-cyclohexyl]-3-phenylpropananoyl]bornane-10,2sultam (C 25 H 35 NO 3 S,M r=429.60),a derivative of camphorsultam,crystallizes in the monoclinic space group P2 1 /c with a=10.3301(7),b=19.4040(13),c=11.8106(8),β=100.5580(10)°,V=2327.3(3) 3,Z=4,D c=1.226 g/cm 3,λ=0.71073,μ(MoKα)=0.165 mm-1 and F(000)=928.X-ray diffraction analysis reveals that the six-membered ring of sultam shows a boat form (Fig.1).The planes constructed by (C(4),C(5),C(6),C(7)) and (C(7),C(8),C(9),C(4)) form a dihedral angle of 69.5°.The C(1)-C(2)-C(3) plane forms dihedral angles to the aforementioned planes of 89.8(1) and 85.9(3)°,respectively.And molecules are linked via hydrogen bonding (C-H···N/O) interactions.     

Synthesis and structure of [(p-phenylenedimethylene) Bis [diphenylphosphine]]-Bis[(acetylacetonato) carbonylrhodium(I) and its reaction product with inorganic azides,azidocarbonylbis (triphenylphosphine) rhodium(I)

Journal of Structural Chemistry -     

1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺的性质

制备了功能化离子液体1-丁腈-3-甲基咪唑双三氟甲基磺酸亚胺。在T为283.15-353.15 K温度范围内,测定了该功能化离子液体的密度、动力粘度、电导率及折光率。讨论了亚甲基的增减对该类功能化离子液体的密度、动力粘度、电导率及折光率等性质的影响,并与传统咪唑类、吡啶类离子液体物理化学性质的变化趋势进行了对比。通过经验方程计算了该功能化离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数。讨论了Vogel-Fulcher-Tamman (VFT)方程和Arrhenius方程的适用性,得出VFT方程适用于该功能化离子液体,而Arrhenius方程并不适用。有关研究对新型离子液体的合成及其工业化的应用具有十分重要的意义。     

Resin-OsO4-金鸡纳生物碱:一种在(E)-二苯乙烯不对称双羟化反应中可循环使用的高效催化剂

用改进的方法把季铵盐共价结合在Merrifield树脂上作为离子交换剂与K2O5O4作用制成Resin—OsO4催化剂，在NaH存在下，以DMF作溶剂，在70℃下奎宁或奎尼丁与1，4-二氯二氮杂萘反应高产率地生成(QN)2PHAL或(QD)2PHAL，Resin—OsO4通过简单过滤可定量回收，回收的催化剂重复使用五次，其活性不变，Resin—OsO4-(QN)2PHAL或(QD)2PHAL催化体系在(E)-二苯乙烯的不对称双羟化反应中的化学产率为84～91％，立体选择性为96-99％ee。