Chiral Camphor-Based 1,3- and 1,4-Amino Alcohols and Aminodiols as Ligands for Diethylzinc Addition to Aldehydes

Syntheses of (1R,2S,3R,4S)-1,7,7-trimethyl-2-pyridin-2-ylmethylbicyclo[2.2.1]-heptane-2,3-diol (7), (1R,2S,3R,4S)-1,7,7-trimethyl-2-[(6-methyl)-pyridin-2-ylmethyl-bicyclo-[2.2.1]heptane-2,3-diol (13), and (1R,2S,2’R,4R)-1,7,7-trimethyl-2-piperidin-2-ylmethyl-bicyclo[2.2.1]heptan-2-ol (19b) from commercially available (d)-camphor (1) are described. Key steps of the syntheses involved substrate-controlled diastereoselective alkylation and platinum oxide-catalyzed hydrogenation reactions. These compounds, and other intermediate amino alcohols in their syntheses, were successfully utilized as ligands in enantioselective diethyl zinc (Et2Zn) addition to benzaldehyde with moderate enantioselectivity.

Synthesis of new chiral 1,2,3,4-tetrahydroisoquinoline β-amino alcohols from L-DOPA

Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived β-amino alcohols were synthesized from L-DOPA in good yields. The structures of the target compounds were confirmed by ^1H NMR, ^13C NMR and MS.

A Convenient Method for the Synthesis of Chiral N-Protected 1,2-Amino Alcohols via the Reduction of the Aminoketones

A series of optically active N-protected 1,2-amino alcohols were synthesized via the reduction of the corresponding a-aminoketones starting from the readily available L-amino acids.

Synthesis of Unprotectedα-Tertiary Amines and 1,2-Amino Alcohols from Vinyl Azides by Light Induced Denitrogenative Alkylarylation/Dialkylation

Sterically congestedα-tertiary primary amines are ubiquitous substructures in pharmaceutical and agrochemical agents yet are challenging to access.Herein,straightforward photoredox-catalyzed access to structurally diverseα,α,α-trisubstituted primary amines from denitrogenative alkylarylation or dialkylation of vinyl azides with N-hydroxyphthalimide(NHPI)esters and cyanoarenes or aryl aldehydes has been developed.The use of vinyl azide as a precursor to a primary aminewas enabled by the dual role of the Hantzsch ester to form an electron donor-acceptor complex and serve as a sacrificial reductant.This strategy provides a modular synthesis ofα-tertiary primary amines,including unprotected 1,2-amino alcohols,from simple materials with excellent functional group tolerance.The synthetic applicability of this method was demonstrated by streamlined access to 2,2-disubstituted tetrahydroquinolines.Preliminary investigations support two parallel reductive photocatalytic cycles allowing for the denitrogenative alkylarylation or dialkylation of vinyl azides via decarboxylative radical addition followed by heteroradical cross-coupling betweenα-amino radicals and aryl anion radicals or ketyl anion radicals.

Highly Regio-Selective Synthesis of β-Amino Alcohol by Reaction with Aniline and Propylene Carbonate in Self Solvent System over Large Pore Zeolite Catalyst

The nucleophilic ring opening of epoxides with amines is a well known route for the synthesis of β-amino alcohols. The use of carbonates offers significant advantages over epoxides as they are far less hazardous materials, safe for handling, do not require high-pressure equipment and most notably the possibility of solvent less reactions. In this work, utilization of zeolite as host catalyst in the reaction media for synthesis of β-amino alcohols without using solvent is reported.

Synthesis of new chiral 1,2,3,4-tertrahydroisoquinoline β-amino alcohol for asymmetric diethylzinc addition to aryl aldehydes(Ⅰ)

Four new chiral 1,2,3,4-tetrahydroisoquinoline-derived G-amino alcohols were synthesized from commercially available LDOPA. These ligands were evaluated in the asymmetric addition of diethylzinc to benzaldehydes and showed different catalytic activities （up to 86% ee）. The solvent played an important role in the enantioselective process. The transition state models were proposed to explain the reversion of the product configuration.

Enantioselective addition of diethylzinc to aryl aldehydes catalyzed by 1,2,3,4-tetrahydroisoquinoline β-amino alcohol

A highly effective,new chiral 1,2,3,4-tetrahydroisoquinoline catalyst 1 for the diethylzinc addition to aryl aldehydes has been investigated.Using 10 mol%of this chiral catalyst,secondary alcohols can be obtained in up to 87%yield and 99.5%ee under mild conditions.

Synthesis of a New Chiral Cyclicβ-Amino Alcohol

A new chiral cyclic β-amino alcohol (R)- 1 -(l '-amino-2'-naphthylethyl)-cyclopentanol2, which had notbeen reported previously, was prepared from (R) - 3 - (2 - naphthy1 )- alanine 3.

Promoting electrocatalytic alcohols oxidation coupled with H_(2) production via ligand intercalation strategy

Electrochemical alcohol oxidation,the alternate of oxygen evolution reaction,has been recognized as an effective way to produce value-added chemicals coupled with H2 production.However,the current researches still suffer from the low reaction rate and Faradaic efficiency(FE)that limits the overall efficiency.Herein,we report a ligand intercalation strategy to enhance the current density of alcohol electrooxidation by intercalating sodium dodecyl sulfonate(SDS)in the interlayer of Co(OH)_(2)catalyst(Co(OH)_(2)-SDS).For instance,the Co(OH)_(2)-SDS shows obviously enhanced current density for glycerol electrooxidation than that of pure Co(OH)_(2).The corresponding glycerol conversion rate and H2 production rate reach 0.35 mmol·cm^(−2)·h^(−1)and 9.1 mL·cm^(−2)·h^(−1)at 1.42 V vs.reversible hydrogen electrode,which are 2.2-and 1.9-fold higher than that of Co(OH)_(2).The yield of formate reaches 86.6%with selectivity of 95.3%at high glycerol conversion of 95.1%(with FE of 83.3%for glycerol oxidation).The Co(OH)_(2)-SDS is demonstrated efficient for different alcohols with enhanced performance.We confirmed that the intercalation of SDS in Co(OH)_(2)can promote the generation and exposure of CoOOH reactive sites,and also facilitate the adsorption of alcohol,thus enabling high reaction rate.

菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症的改善作用及其机制

目的观察菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症的改善作用并探讨其机制。方法雌性SD大鼠随机分为正常组、假手术组、模型组、雌激素对照组、菟丝子低剂量组、菟丝子高剂量组,每组10只。除正常组、假手术组外,各组均采用双侧去卵巢手术建立大鼠绝经后骨质疏松症模型;假手术组在暴露卵巢后切除卵巢周围脂肪组织,不切除卵巢;正常组正常喂养不做任何处理。于建模后两周起开始给药,菟丝子低剂量组、菟丝子高剂量组分别按0.7 g/kg、1.4 g/kg给予菟丝子乙醇提取物灌胃,雌激素对照组给予非甾体雌激素己烯雌酚灌胃,正常组、假手术组及模型组给予等容积生理盐水灌胃,连续给药12周。采用双能X线检测大鼠股骨骨密度,HE染色观察股骨组织病理形态,RT-PCR法检测股骨组织miR-21-5p,Western blotting法检测股骨组织Fas配体(FasL)蛋白。结果模型组股骨骨密度小于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组股骨骨密度大于模型组(P均<0.05)。正常组及假手术组骨皮质骨膜及骨内膜光滑,骨小梁形态粗细基本一致,皮质区仅出现轻微的松质骨改变;模型组骨小梁明显变薄,间隔增宽,互不相连,排列不齐,皮质区出现严重的松质骨改变;雌激素对照组、菟丝子低剂量组、菟丝子高剂量组骨小梁间距较模型组均有不同程度的减小,且皮质区松质骨改变变轻。模型组股骨组织miR-21-5p表达高于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组miR-21-5p表达低于模型组(P均<0.05)。模型组股骨组织FasL蛋白表达低于正常组、假手术组,雌激素对照组、菟丝子低剂量组、菟丝子高剂量组FasL蛋白表达高于模型组(P均<0.05)。结论菟丝子乙醇提取物灌胃对大鼠绝经后骨质疏松症具有改善作用,其机制可能与调控miR-21-5p及其下游蛋白FasL有关。

Schiff-base Amino Alcohol-zinc Complex for Enantioselective Addition of Phenylacetylene to Aromatic Ketones

A complete study of the asymmetric addition of phenylacetylene to ketones catalyzed by Schiff-base amino alcohol-Zn complex is reported in this article. The Schiff-base amino alcohols were easily prepared from amino acids in three steps. When the amount of ligand was 1%（molar fraction）, an e.e. value up to 94% was obtained. A series of practical chiral ligands were applied in the enantioselective addition of phenylacetylene to ketones without adding another stronger Lewis acid except zinc.

Enantioselective Addition of Phenylacetylene to Ketones Catalyzed by Titanium（IV） Complexes of N-Sulfonylated β-Amino Alcohols

The easily prepared and recoverable chiral N-sulfonylated fl-amino alcohol 2 in combination with Ti（OPr-i）4 was found to be an effective chiral catalyst for the enantioselective addition of alkynylzinc to ketones, which gave the useful products, i.e. chiral tertiary propargyl alcohols, with the ee up to 92%.

Tunable synthesis of furfurylamines orβ-amino alcohols via Ru-catalyzed N–H functionalization using biomass-derived polyols

We report the highly efficient conversion of readily available biomass-derived polyols with amines to valuable furfurylamines orβ-amino alcohols compounds using ruthenium catalysis.The reaction outcome is readily tuned by the simple addition of 4Åmolecular sieves(furfurylamines vs.β-amino alcohols)with high chemo-selectivity.The proposed reaction mechanism involves ruthenium-catalyzed hydrogen borrowing for the reduction of the imine intermediate and C–C bond cleavage of polyols via a retro-aldol process.A series of arylamines was suc-cessfully transformed into the desired products with moderate to good yields.

Enantioselective addition of Et_2Zn to aldehydes catalyzed by chi-ral aliphatic β-amino alcohols

This paper describes the preparation of two new optically active aliphatic β-amino alcohols (R)-5,5-dimethyl-2-(dimethy-lamino)-1,1-diphenyl-1-hexanol (1a) and (S)-8,8-dimethyl-2-(dimethylamino)-1, 1-diphenyl-1-nonanol (1b). They were synthesized by methylation of the corresponding β-amino alcohols 2a and 2b. Compounds la and 1b catalyze the addition of diethylzinc to various aldehydes enantioselectively. The catalyst structure-enantioselectivity relationships were discussed.

Cu(OTf)_2-catalyzed ring-opening of epoxides with anilines:A convenient synthesis of β-amino alcohols

The regioselective ring-opening of epoxides with aniline and p-chlorop niline catalyzed by copper(Ⅱ) triflate provides the corresponding β-amino alcohols in excellent yields.

聚乙烯醇纤维金属配合物的合成和表征

以聚乙烯醇纤维(PVA)为配体原料,分别与FeCl3、NiCl2、CuCl2和Pb(Ac)2反应,制备了宏观上仍保持原纤维形态的PVA Fe(Ⅲ)、PVA Ni(Ⅱ)、PVA Cu(Ⅱ)、PVA Pb(Ⅱ)纤维配合物(用PVA M表示).用红外光谱仪分别对PVA和4种配合物在4000～400cm-1范围进行傅立叶变换红外光谱测量,对各PVA M的FTIR主要吸收峰做了经验归属,并与PVA的相应吸收峰做对比分析,结果表明,与金属离子形成配合物后,PVA分子中O—H氢键缔合状态被破坏,向高波数位移了65～86cm-1,PVA中的羟基氧与金属离子发生配位作用.PVA Fe(Ⅲ)的XPS显示,PVA中O1s只出现532.5eV单峰,而PVA Fe(Ⅲ)中O1s分裂为531.4eV和532.3eV两个峰,且Fe2p只有一个峰710.9eV,比FeCl3的结合能值711.2eV下降,说明OH氧与Fe3+形成配位键.

Ru-(S)-BINAP/γ-Al_2O_3催化剂上苯乙酮及其衍生物的多相不对称加氢反应

在温和条件下制备了Ru (S) BINAP/γ Al2 O3 催化剂 ,考察了其催化苯乙酮及其衍生物不对称加氢的活性 .在KOH 异丙醇溶液中 ,在c(KOH) =0 0 4mol/L ,氢气压力 5MPa和 10℃条件下 ,(1S ,2S) DPEN手性修饰剂修饰的Ru (S) BINAP/γ Al2 O3 催化剂具有较高的活性和对映选择性 ,反应 2 8h后苯乙酮的转化率可达 10 0 % ,(R) 苯乙醇的ee值可达 75 0 % .

催化选择性氧化苯甲醇合成苯甲醛反应研究

提出了清洁催化氧化苯甲醇合成苯甲醛的新途径。反应采用30%双氧水为氧化剂,在温和的酸性条件下进行,无任何有机溶剂,无相转移剂,无卤素存在。当以钨酸钠和酸性配体为催化剂时,在大多数情况下,配体的酸性越强,反应物的转化率和目标产物的选择性越高。对于一些酚类配体、L(+)抗坏血酸等来说,虽然酸性较弱,但反应的转化率和选择性却很高,这说明除了配体的酸效应以外,还存在配体的配位效应。杂多酸作为催化剂有较好的催化活性,使用不同的杂多酸催化剂时,随着酸性的增强(磷钨酸>磷钼酸>硅钨酸),反应物的转化率和目标产物的选择性都逐渐提高。在相同的条件下,磷钨酸的效果最佳。