一种新型线性手性聚（联萘酚-炔）的合成及其在Et2Zn不对称醛加成反应中的应用（英文）

(S)-5,5’-二溴-6,6’-二(4-三氟甲基苯基)-2,2’-联萘酚与(S)-5,5’-二乙炔基-6,6’-二丁基-2,2’-二丁氧基-1,1’-联萘酚通过Pd催化的Sonogashira反应合成了一种新的手性线性高分子聚合物,研究了这种高分子在Et2Zn不对称醛加成反应中的应用.结果表明这种高分子在Ti(OiPr)4的存在条件下展示了良好的反应活性.而且,这种高分子配体在循环利用10次后可仍然保持较好的活性.     

可回收(S)-脯氨醇衍生物在催化查尔酮类化合物不对称环氧化反应中的催化性能研究

将以L-脯氨酸为原料合成的光学活性脯氨醇衍生物((S)-2-吡咯烷基-α,α-二(α-萘基)甲醇1),作为有机小分子催化剂,在催化8种α,β-不饱和酮的不对称环氧化反应中表现出较好的立体选择性(58.0~84.6?)和催化活性(58.0~89.7%).反应结束后,通过简单的酸碱调整,可使催化剂回收和重复使用.循环使用5次,催化剂的回收率均在93~97%之间,催化剂的催化活性和立体选择性无明显改变.     

不对称催化氧化制备(S)-泮托拉唑

以(2S,3S)-N,N’-二苄基-酒石酸二酰胺和Ti(O-Pri)4形成的手性络合物为催化剂,枯烯过氧化氢为氧化剂,不对称催化氧化制备了(S)-泮托拉唑,转化率87%,纯化后的化学纯度>99.5%,光学纯度99.5%,硫醚含量<0.1%,砜含量<0.1%,其结构经1H NMR确证。     

一种新型双亲性有机小分子催化剂在水相体系中催化环己酮与硝基烯烃直接不对称Michael加成反应

设计合成了一系列基于脯氨酸巯基咪唑衍生物的新型双亲性有机小分子催化剂,在水相中加入酸作为助催化剂,可以高效高选择性的催化环己酮与硝基烯烃的不对称Michael加成反应,非对映选择性和对映选择性分别高达99：1和96%.     

二苯基脯氨醇及其衍生物对前手性酮的不对称催化还原研究进展

对(S)-α,α-二苯基脯氨醇及其衍生物对前手性酮的不对称催化还原研究进行了综述, 表明它们具有催化还原产率高、对映选择性好的作用, 是一类性能优秀的不对称还原反应的有机小分子催化剂.     

手性联二萘酚衍生物催化的苯乙炔与苯甲醛不对称加成反应

以手性联二萘酚为原料,合成了3,3′位取代的手性联二萘酚衍生物,研究了该衍生物配体在二乙基锌存在下,催化苯乙炔与苯甲醛的不对称加成反应,产物的产率为73%,e.e.值为40%。 研究结果表明,手性联二萘酚衍生物结构的微小变化导致催化产物构型的改变。     

邻羟基苄醇与邻羟基苯乙烯的催化不对称[4+2]环加成反应——手性色满骨架的立体选择性构建

研究了手性磷酸催化下邻羟基苄醇和邻羟基苯乙烯的不对称［4+2］环加成反应,立体选择性地一步构建了手性2,4-二取代四氢色满骨架,该反应具有较高的收率、中等到较高的对映选择性和很好的非对映选择性（最高产率为78%,最高ee值为72%,dr值基本都大于95∶5）.带有不同取代基的多种邻羟基苄醇和邻羟基苯乙烯均适用于该反应,电子效应对于该反应的对映选择性有一定影响,其中连有供电子基的底物具有更高的反应活性和对映选择性.由邻羟基苄醇原位生成的邻亚甲基苯醌中间体和邻羟基苯乙烯可以同时与催化剂手性磷酸形成双重氢键,对于促进反应的进行和控制该反应的对映选择性起着至关重要的作用.     

构建色满骨架的简便方法: (–)-4’-羟基-7-甲氧基黄烷的不对称合成

通过不对称还原产生手性中心以及微波催化的芳环上C―O键的生成构建出苯并吡喃骨架,首次对映选择性地合成了天然产物(–)-4’-羟基-7-甲氧基黄烷. 主要的合成特色包括路线简短, 反应过程手性中心的ee值保持, 有两种可供选择的关环前体.     

手性联二萘酚衍生物催化芳香醛的不对称炔基锌加成反应

以手性联二萘酚为原料,合成了3,3’位取代的手性联二萘酚衍生物,研究了在该衍生物配体、二乙基锌和三乙胺条件下的苯乙炔对芳香醛的不对称加成反应,得到较好产率(43%～71%)的炔丙醇,ee值最高为68%。     

聚合物负载的手性联二萘酚的合成及其在不对称催化中的应用进展

作为一种有机配体, 手性1,1'-联二萘酚(BINOL)被广泛应用于过渡金属催化的均相不对称有机反应. 为克服均相催化剂不易回收重复使用等缺陷, 人们深入研究了聚合物负载手性BINOL催化剂的方法. 总结了近年来聚合物负载手性BINOL催化剂的合成及其在不对称有机催化中的应用, 并对负载型BINOL催化剂进行了展望.     

硫脲催化硝基烯与硫叶立德的不对称Michael加成反应

基于密度泛函理论研究了氯代苯基硫脲催化的硝基苯乙烯与硫叶立德的Michael加成反应,确定了控制反应立体选择性的C―C键形成步骤的过渡态结构,计算了过渡态的相对能量和反应势垒,弄清了硫脲催化的微观反应机理,探讨了硫脲催化性能的微观本质.结果表明,反应有利于反式Michael加成产物的形成,硫脲在反应中作为质子给体,首先与质子受体硝基苯乙烯形成双氢键配合物,通过授受体间的电荷转移活化硝基苯乙烯的β-C原子增强其亲电性,有利于硫叶立德的亲核进攻.     

Asymmetric Michael addition of α-nitro-ketones using catalytic peptides

Peptide-based catalysts have been developed that promote the asymmetric Michael addition of nitroalkanes. The most effective peptides contain a β-turn structural element as well as a basic histidine and an arylsulfonamide-protected arginine. Excellent yields with enantioselectivities of up to 74% ee have been observed.     

(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.     

L-丙氨酰Betti碱催化环己酮对硝基烯不对称Michael加成反应

合成了3个手性Betti碱的L-丙氨酰衍生物, 并用它们来催化环己酮与硝基烯的Michael加成反应. 发现1a是其中最有效的催化剂, ee值最高大于99%, dr值最高大于99∶1. 考察了催化剂结构与用量、添加剂用量、底物结构等因素对反应的化学产率和光学收率的影响.     

Sc(OTf)3: A Highly Efficient and Renewable Catalyst for Michael Addition of Indoles to Nitroolefins in Water

A catalytic amount of scandium trifluoromethanesulfonate [Sc(OTf)₃] (2.5 mol%) was used to catalyze the Michael addition of indoles to nitroolefins in water to afford the corresponding 3-alkylated indoles in good to excellent yields. The short reaction times, excellent yields, and renewability of the catalyst are noteworthy.     

Wang Resin-supported Enantioselective Catalysts for the Asymmetric Michael Additions ofAcetone to β-Nitroolefins

Two Wang resin-supported (1R,2R)-(+)-1,2-DPEN(DPEN=diphenylethylenediamine) catalysts were synthesized from cyanuric chloride and trimesoyl chloride, respectively. These two catalysts were characterized by FTIR, TGA and elemental analysis. The results demonstrated that (1R,2R)-(+)-1,2-DPEN was successfully bonded to the surface of Wang resin through the amido linkage. Subsequently, the asymmetric Michael addition of acetone to β-nitrostyrene was employed to evaluate their catalytic performance. It was found that the catalyst generated from trimesoyl chloride exhibited much better catalytic behavior than our previously reported catalyst, likely attributed to the multiple hydrogen-bond interaction between β-nitrostyrene and amide group, which made the catalytic transition intermediates more stable. Under the optimal conditions, 76.1% β-nitrostyrene conversion and 93.8% enantioselectivity were obtained. Finally, the generality of this catalyst was examined with Michael additions of acetone to β-nitroolefins and excellent enantioselectivities(91.9% to 99.9%) were achieved.     

Efficient Route to Highly Functionalized Chalcone-Based Pyranocoumarins via Iodine-Promoted Michael Addition Followed by Cyclization of 4-Hydroxycoumarins

Molecular iodine is used as an efficient promoter in the regioselective synthesis of highly functionalized chalcone-based pyranocoumarin derivatives using 4-hydroxycoumarin in acetic acid solvent at 100 °C. Under optimized reaction conditions, our protocol (Michael addition followed by intermolecular cyclization) has tolerance for many functional groups and gave products in good to excellent yields (75–98%) within 1–2 h.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource: Full experimental and spectral details.]