聚[(S)-3-乙烯基-2,2'-二羟基-1,1'-联萘]的钛配合物催化三乙基铝对醛的不对称加成反应

通过维蒂希反应合成了(S)-3-乙烯基-2,2'-甲氧甲氧基-1,1'-联萘.将单体(S)-3-乙烯基-2,2'-甲氧甲氧基-1,1'-联萘用偶氮二异丁腈作引发剂进行自由基聚合得到了聚[(S)-3-乙烯基-2,2'-二甲氧基甲氧基-1,1'-联萘].该聚合物上的MOM保护基通过酸脱除获得手性螺旋聚合物聚[(S)-3-乙烯基-2,2'-二羟基-1,1'-联萘].将手性螺旋聚合物聚[(S)-3-乙烯基-2,2'-二羟基-1,1'-联萘]与Ti(O-i-Pr)4形成的配合物应用于三乙基铝与醛的不对称加成反应中,获得了较好的对映选择性,ee值最高为85%.更重要的是,这种聚合物还可以被回收利用多次且催化活性没有明显降低.     

螺旋聚[(S)-3-(二苯羟甲基)-3′-乙烯基-2,2'-二羟基-1,1'-联萘]的合成、光学性质及其在杂-Diels-Alder反应中的不对称诱导

合成了一种基于联萘酚的新型手性单体,(S)-3-(二苯羟甲基)-3'-3-乙烯基-2,2'-二羟基-1,1'-联萘(5).通过由偶氮异丁腈(AIBN)引发的自由基聚合得到聚[(S)-3-(二苯羟甲基)-3'-3-乙烯基-2,2'-二羟基-1,1'-联萘](P-5),旋光、紫外-可见光谱、圆二色谱表征结果表明P-5以单手性螺旋结构的形式存在于溶液中.考察了螺旋齐聚物P-5在催化苯甲醛与Danishefsky双烯烃的杂-Diels-Alder(HDA)反应中的不对称诱导作用,所得加和产物的ee值达71%,P-5可以被回收重复使用而保持催化活性不变.     

(-)-双(薄荷基甲酰基)苯基氧化膦的合成及在自由基光聚合中的螺旋选择性

以苯基二氯化膦和薄荷基甲酸为原料, 合成了一种手性双酰基膦氧化物光引发剂(-)-双(薄荷基甲酰基)苯基氧化膦. 采用核磁共振谱、 质谱及元素分析确定了该化合物的结构, 并测定了其螺旋诱导能力. 结果表明, (-)-BMPPO在引发自由基光聚合大位阻的单体甲基丙烯酸-1-苯基二苯并环庚酯(PDBSMA)的反应中具有螺旋选择性. 所得聚合物具有高度全同结构并显示出光学活性, 说明该聚合物形成了稳定的单手性螺旋链构象. 降低单体与引发剂的投料比及提高聚合温度有利于增加反应的螺旋选择性. 在手性薄荷醇溶剂中, 由(2,4,6-三甲基苯甲酰基)二苯基氧化膦(TPO)引发单体PDBSMA的光聚合反应也具有螺旋选择性, 但螺旋选择性很小.     

由孕甾-3S,5R,6R,16S,20S-五醇合成黄体酮

首次利用薯蓣皂甙元降解产物, 孕甾-3S,5R,6R,16S,20S-五醇(3)完成了黄体酮的合成. 孕甾-3S,5R,6R,16S,20S-五醇可方便地通过薯蓣皂甙元经由30%双氧水原地产生的过酸氧化降解得到. 它经过缩酮化反应、乙酰化反应和串联的脱缩酮-溴代乙酰化反应被转化成关键合成中间体16R-溴孕甾-3S,5R,6R,20S-四醇-3,6,20-三乙酸酯(6). 化合物6经锌粉还原、C-3乙酰氧基选择性水解氧化反应和C-5羟基消除反应生成6R,20S-二乙酰氧基孕甾-4-烯-3-酮(10). 化合物10经C-6乙酰氧基还原和C-20乙酰氧基水解-氧化生成目标分子黄体酮. 合成经10步反应, 反应总收率达45.1%.     

6,6'-取代1,1'-联二萘酚衍生的手性磷酸的合成

1,1'-联二萘酚(1)经溴代反应制得6,6'-二溴-1,1'-联二萘酚(2);2经苄基保护羟基制得2,2'-二苄氧基-6,6'-二溴-1,1'-联二萘(3);3经Ullmann缩合在6,6'-位引入甲氧基制得2,2'-二苄氧基-6,6'-二甲氧基-1,1'-联二萘(4b);3经Kumada偶联反应在6,6'-位引入正己基制得2,2'-二苄氧基-6,6'-二正己基-1,1'-联二萘(4c);4b和4c经还原脱去苄基制得6,6'-位取代1,1'-联二萘酚(5b和5c);2,5b和5c分别与三氯氧磷反应合成了3种1的6,6'-位取代手性磷酸(6a~6c),其结构经1H NMR和31P NMR表征。其中6c为新化合物。     

手性氨基醇诱导联苯构象转化制备轴手性联苯化合物

在(S)-氨基丙醇及(R)-氨基丙醇手性臂的作用下, (M/P)-4,4'-二甲氧基-5,6,5',6'-二次甲二氧基-2-甲酸酯-2'-甲酰氨联苯经构型转化, 制备了光学纯轴手性联苯化合物(P, S)-3a 和(M, R)-3a. 测定了(P, S)-3a 的晶体结构及CD 光谱. 结果表明, 化合物(P, S)-3a 晶体属单斜晶系, P2(1)空间群, 晶胞参数为a＝12.122(2) Å, b＝8.9911(18) Å, c＝12.779(3) Å, β＝112.38(3)°, 在晶体中存在两组分子间氢键相互作用, 一组氢键由羟基氢与另一分子酰胺基团的羰基氧组成O-H…O,另一组由酰胺基团的NH 与另一分子酰胺基团的羰基氧构成N-H…O, 每一分子通过四个氢键与另外两个分子相连,构成棒状结构. 由CD 光谱确定了(M, R)-3b 的立体构型. 此外, 由(P, S)-3a 合成了轴手性化合物(P)-2,2'-二羟甲基-4,4'-二甲氧基-5,6,5',6'-二亚甲二氧基-联苯(6a).     

(S)-6-丙烯酰基-2-甲氧基-2’-特戊酰氧基-1,1’-联萘负离子聚合合成螺旋聚α,β-不饱和酮

在三氯化铝作用下(S)-2-甲氧基-2’-特戊酰氧基-1,1’-联萘经酰基化反应生成(S)-6-(3-氯丙酰基)-2-甲氧基-2’-特戊酰氧基-1,1’-联萘2a.在三乙胺存在条件下2a脱去氯化氢生成了(S)-6-丙烯酰基-2-甲氧基-2’-特戊酰氧基-1,1’-联萘3.将单体3用正丁基锂作引发剂在甲苯溶液中进行了负离子聚合.聚合物3的比旋光度的绝对值[α]25589为+96,是其单体3的8倍.通过对照聚合物和单体以及模型化合物如(S)-6-丙酰基-2-甲氧基-2’-特戊酰氧基-1,1’-联萘2b和(S)-6-庚酰基-2-甲氧基-2’-特戊酰氧基-1,1’-联萘2c之间的比旋光度和圆二色谱,确认聚合物3以单手性螺旋结构的形式存在于溶液中.聚合物3的各向异性因子g值是其单体的18倍,这也证实了聚合物3的单手性螺旋结构.     

基于2,5-二(4''''-甲酰基苯基)苯乙烯的螺旋链光学活性聚合物的合成与表征

通过2,5-二溴苯乙烯与对甲酰基苯硼酸的Suzuki偶联反应得到2,5-二(4'-甲酰基苯基)苯乙烯.在催化剂量的冰乙酸存在下,与光学纯的(S)-(-)-α-甲基苄胺或(R)-( )-α-甲基苄胺发生缩和反应,得到了一对手性非外消旋单体,( )-2,5-二{4'-[(N-(S)-α-甲基苄亚胺基)次甲基]苯基}苯乙烯和(-)-2,5-二{4'-[(N-(R)-α-甲基苄亚胺基)次甲基]苯基}苯乙烯.以偶氮二异丁腈(AIBN)或过氧化苯甲酰(BPO)为引发剂,经自由基溶液聚合得到光学活性聚合物.比旋光度、紫外-可见吸收光谱以及圆二色光谱研究表明,聚合物主链可能形成了某一方向占优的稳定螺旋构象,且该螺旋构象的旋光方向与单体的旋光方向相反.聚合条件对聚合物的光学活性有很大影响,在极性较大的芳香族溶剂和较高温度下得到的聚合物具有和单体相差更大的比旋光度.侧基的手性基团脱除后,聚合物仍具有一定的旋光性,说明聚合过程中形成的螺旋手性具有一定的记忆效应.     

手性联萘基-2,2'-联吡啶及其衍生物的合成及其在不对称合成中的应用

利用Kröhnke方法,以芳基乙酮为原料一锅法简洁地合成了6-芳基-6'-溴-2,2'-联吡啶2b~2d。 通过(R)-3-(4,4,5,5-四甲基-1,3,2-二噁唑硼烷基)-2,2'-乙氧基-1,1'-联萘((R)-1)与6-溴-2,2'-联吡啶及其衍生物2a~2d的Suzuki偶联, 合成了4种手性6-[3-((R)-2,2'-二乙氧基-1,1'-联萘)基]-2,2'-联吡啶(R)-3a~3d。 将配体(R)-3a~3d应用于苯乙酮的不对称氢转移反应中,配体(R)-3a给出92%的转化率和4%的对映体过量(ee)值。     

酚氧基联烯基醚单体的原子转移自由基聚合研究

以具有较高活性的酚氧基联烯基醚(POA)和对叔丁基酚氧基联烯基醚(t-BuPOA)为研究对象, 研究了不同引发 剂/配体体系对其原子转移自由基(ATRP)聚合行为的影响. 发现在2-溴代丙酸甲酯/溴化亚铜/4,4’-二庚基联吡啶(2-MBP/CuBr/dHbpy)和对甲苯磺酰氯/溴化亚铜/三-(N,N-二甲基氨基乙基)胺(p-TsCl/CuBr/Me6TREN)两种ATRP反应体系中, POA的聚合都遵循ATRP反应的机理.     

Synthesis of ansa-2,2′-bis[(4,7-dimethyl-inden-1-yl)methyl]-1,1′-binaphthyl and nsa-2,2′-bis[(4,5,6,7-tetrahydroinden1-yl)methyl]-1,1′-binaphthyltitanium and -zirconium dichlorides

2,2′-Bis[(4,7-dimethyl-inden-1-yl)methyl]-1,1′-binaphthyl and [2,2′-bis[(4,5,6,7-tetrahydroinden-1-yl)methyl]-1,1′-binaphthyl]titanium and -zirconium dichlorides have been synthesized from 2,2′-bis(bromomethyl)-1,1′-binaphthylene. 2,2′-Bis(bromomethyl)-1,1′-binaphthylene was alkylated with the lithium salt of 4,7-dimethylindene to yield 2,2′-bis[1-(4,7-dimethyl-indenylmethyl)]-1,1′-binaphthylene (S)-(−)-9. The lithium salt of 9 was metalated with either titanium trichloride followed by oxidation or zirconium tetrachloride to give titanocene dichloride (S)-(+)-10 and zirconocene dichloride 11. The known complexes ansa-[2,2′-bis[(1-indenyl)methyl]-1,1′-binaphthyl]titanium and -zirconium dichlorides were formed and hydrogenated to ansa-[2,2′-bis[(4,5,6,7-tetrahydroinden-1-yl)methyl]-1,1′-binaphthyl]titanium and -zirconium dichlorides 12 and 14 or to ansa-[2,2′-bis[(4,5,6,7-tetrahydroinden-1-yl)methyl]-5,5′,6,6′,7,7′,8,8′-octahydro-1,1′-binaphthyl]titanium dichloride 13 whose solid state structure was determined by X-ray crystallography. Complex 13 adopts a C₁-symmetrical conformation in the solid state, but is conformationally mobile in solution, exhibiting C₂-symmetry in its room temperature NMR spectra.     

A modular approach to a new class of phosphinohydrazones and their use in asymmetric allylic alkylation reactions

A group of five phosphino hydrazones with a pendant binaphthyl unit as a chiral modifier has been synthesized from non-racemic 2,2′-bis(bromomethyl)-1,1′-binaphthyl and 3,3′-diiodo-2,2′-bis(bromomethyl)-1,1′-binaphthyl as the key intermediates. Their efficiency as chiral ligands in palladium-catalyzed allylic alkylation reactions has been investigated showing up to 95% ee under optimized conditions. X-ray diffraction structures of mono- and dimeric Pd complexes are also reported.     

Synthesis of New Dioxacyclophanes Derived from 1,1′-Binaphthyl-2, 2′-diol

Abstract

The Williamson reaction between (R,S)-[1,1′-binaphthyl]-2, 2′-diol 1 and (R,S)-2,2′-bis (bromomethyl)-1,1′ binaphthyl 2 in acetone, gave the diastereoisomeric dioxacyclophanes (R?, S?)-3a and (R?, R?)-3b in high yield.     

Reductive cleavage of axially disymmetric tertiary amines and quaternary ammonium salts by lithium aluminium hydride. Synthesis of new 1,1′-binaphthyl substituted amines

Axially disymmetric tertiary amines or quaternary ammonium salts $\text{A}$ are synthesized by double alkylation of primary or secondary amines with racemic or optically pure 2,2′-bis (bromomethyl)-1,1′-binaphthyl. Their reductive cleavage by lithium aluminium hydride in refluxing THF leads to chiral secondary or tertiary amines $\text{B}$, substituted by a binaphthyl unit, with high yields and absence of racemization.     

Optically Active Helical Polymer From Anionic Polymerization of (S)-6-Acrylyl-2,2’-dimethoxy-1,1’-binaphthyl

(S)-6-Acrylyl-2,2’-dimethoxy-1,1’-binaphthyl (ADBN) was synthesized and anionically polymerized using n-BuLi as an initiator. The absolute value of specific optical rotation [α]²⁵₅₈₉ of poly-ADBN is ?118.0 and that is about 8 times that of the starting monomer ADBN. Poly-ADBN was confirmed to exist in the form of one-handed helical structure in solution by means of comparing the specific optical rotation, the CD and UV-Vis spectra with that of ADBN and the model compounds such as (S)-6-propionyl-2,2’-dimethoxy-1,1’-binaphthyl (PDBN) and (S)-6-heptanoyl-2,2’-dimethoxy-1,1’-binaphthyl (HDBN). This conclusion was also confirmed by the fact that the g-value of poly-ADBN is about 13 times as high as that of its monomer and model compounds     

BINAS - synthesis and use of a new ligand for propylene hydroformylation

BINAS is a new, very efficient ligand for propylene hydroformylation. BINAS is made by the sulfonation of NAPHOS. Different synthetic routes to NAPHOS are discussed. A new two step synthesis starting from 2,2′-bis(bromomethyl)-1,1′-binaphthyl is described.     

Synthesis of a New Macroperoxy Initiator with Methyl Methacrylate and T-Butyl Peroxy Ester by Atom Transfer Radical Polymerization and Copolymerization with Conventional Vinyl Monomers

In this study, we present the synthesis of poly-MMA macroperoxy initiators obtained by the ATRP of MMA with bromo methyl benzyl t-butyl peroxy ester (t-BuBP) as an initiator, and CuX (X:Br or Cl)/2,2′-bipyridine (bpy) as a catalyst system at 0, 20, 30 and 40°C. The peroxygen groups do not decompose during the ATRP reaction, because low reaction temperatures used for the ATRP reaction are not enough to decompose them. The peroxygen groups of poly-PMMA macroperoxy initiators can lead them to react with a monomer by using appropriate reaction conditions to obtain the block or graft copolymers. For this purpose, poly-MMA macroperoxy initiators were used to synthesize poly(MMA-b-S) block copolymers with S and used for graft copolymerization of polybutadiene (PBd) and natural rubber (RSS-3) to obtain crosslinked poly(MMA-g-PBd) and poly(MMA-g-RSS-3) graft copolymers. Swelling ratio values of the crosslinked graft copolymers in CHCl₃ were calculated. The characterizations of the polymers were achieved by FT-IR, ¹H-NMR, GPC, DSC, SEM, and the fractional precipitation (γ) techniques. The reaction schemes were also performed using the HYPERCHEM 7.5 program. The mechanical properties of the products were investigated.     

The Williamson Reaction: A New and Efficient Method for the Alternate Resolution of 2,2'-Bis(bromomethyl)-1,1'-binaphthyl and 1,1'-Binaphthalene-2,2'-diol

Treatment of 2,2'-bis(bromomethyl)-1,1'-binaphthyl [(R,S)-2] with 1,1'-binaphthalene-2,2'-diol (+)-(R)-1 and cesium or potassium carbonate in refluxing acetone, gave the diastereoisomeric dioxacyclophanes (-)-(R,S)-3a and (+)-(R,R)-3b, both obtained in high yield, and the cyclic tetraether (+)-(R,R,R,S)-4 as isolated side product. Boron tribomide-promoted ether cleavage of 3a and 3b gave optically pure (-)-(S)-2 and (+)-(R)-2, respectively, and the recovered diol (+)-(R)-1. Alternatively, the same reaction sequence furnished the resolved diols (-)-(S)-1 and (+)-(R)-1 from (R,S)-1 and (+)-(R)-2, as well as optically pure 2,2'-bis(chloromethyl)-1,1'-binaphthyl (+)-(R)-5 from the racemic dibromide (R,S)-2 by using boron trichloride for ether cleavage.     

Alkyl halide/tertiary amine as novel initiators for free radical polymerizations of methyl methacrylate,methyl acrylate and styrene

A series of combinations of alkyl halide with tertiary amine such as ethyl α-bromophenylacetate/tris[2-(dimethylamino)ethyl)]amine (αEBP/Me₆TREN), ethyl 2-bromoisobutyrate/triethylamine (EBiB/TEA), and ethyl 2-chloropropionate/N,N,N′,N′,N′′-pentamethyldiethylenetriamine (ECP/PMDETA) have been developed as novel free radical initiators and used for the polymerizations of methyl acrylate (MA), methyl methacrylate (MMA) and styrene (St). The effects of the structure of alkyl halide and tertiary amine on the polymerization of MA were investigated. Gel permeation chromatograph (GPC) and proton nuclear magnetic resonance (¹H NMR) have been utilized to analyze the end group of the obtained poly(methyl acrylate). Electron spin resonance (ESR) spectroscopy was employed to identify the structure of the radicals produced by αEBP/Me₆TREN, and the results indicated that αEBP reacted with Me₆TREN via a single electron transfer (SET) nucleophilic mechanism to produce corresponding ethyl α-phenylacetate radicals which subsequently initiated the polymerization of MA. As both alkyl halide and tertiary amine are commercially available at low cost, non-explosive, and ease of use and storage in comparison with conventional azo, peroxide or persulfate initiators, the combination of alkyl halide and tertiary amine as a free radical initiator is promising for large-scale practical applications.     

Stars and dendrimer‐like architectures by the divergent method using controlled radical polymerization

Using novel multihalide compounds based on 4‐tert‐butylcalix[4,6,8]arenes as initiators, molecularly well‐defined polystyrenes (PS) and poly[alkyl‐(meth)acrylates] could be obtained by atom transfer radical polymerization (ATRP). This core‐first approach and therefore the very same initiators also served to derive star block copolymers. Dendrimer‐like architectures based on poly(ethylene oxide) (PEO) and PS were prepared upon combination of anionic polymerization for the inner PEO part and ATRP for the outer PS shell.