一个取代的1, 5-苯并二氮杂卓的晶体结构及构象研究

用X射线衍射方法测定了4-苯甲酰基-3-(邻氯苯基)-1-乙酸乙酯基-1a-苯基-1,1a,2,3-四氢化-4H-环丙胺-[1,2-a][1,5]-苯并二氯杂卓化合物的晶体结构,晶体结构测定结果表明分子核心骨架二氮杂卓为类船式构象。用动力学模拟退火(SimulatedAnnealing)方法对分子进行了构象分析,结果表明分子中的二氮杂卓七元环具有三种较稳定的构象,其中以船式构象为最稳定,并存在着明显的芳环堆积作用。分子中七元环同时并接苯环和三元环,且环中的N(2)-C(12)-C(11)-N(1)有π键成分,大大限制了七元环构象的相互转换。     

一个取代的1, 5-苯并二氮杂卓的晶体结构及构象研究

用X射线衍射方法测定了4-苯甲酰基-3-(邻氯苯基)-1-乙酸乙酯基-1a-苯基-1,1a,2,3-四氢化-4H-环丙胺-[1,2-a][1,5]-苯并二氯杂卓化合物的晶体结构,晶体结构测定结果表明分子核心骨架二氮杂卓为类船式构象。用动力学模拟退火(SimulatedAnnealing)方法对分子进行了构象分析,结果表明分子中的二氮杂卓七元环具有三种较稳定的构象,其中以船式构象为最稳定,并存在着明显的芳环堆积作用。分子中七元环同时并接苯环和三元环,且环中的N(2)-C(12)-C(11)-N(1)有π键成分,大大限制了七元环构象的相互转换。     

一个取代的三环1,5-苯并二氮杂的晶体结构和构象分析.Ⅱ

用单晶X射线衍射方法测定了6-苯甲酰基-5-(邻氯苯基)-2,3,3a,4,5,6-六氢-3a-苯基-(1,2,3-三乙酸乙酯基)-1H-吡咯啉[1,2-a][1,5-]苯并二氮杂的晶体结构.单斜晶系,空间群P2_1/c,a=1.3235(5)nm,b=1.7142(6)nm,c=1.6204(6)nm,β=100.49(3)°,Z=4,最终偏离因子R=0.062,R_w=0.075.晶体结构测定结果表明分子中二氮杂七元环采取船式构象,动力学模拟退火计算结果的最低能量构象为椅式,两者的能量差不大,表明这种船式椅式的变化是非常容易发生的.     

一个取代的三环1,5-苯并二氮杂(艹卓)的晶体结构和构象分析.Ⅱ

用单晶X射线衍射方法测定了6-苯甲酰基-5-(邻氯苯基)-2,3,3a,4,5,6-六氢-3a-苯基-(1,2,3-三乙酸乙酯基)-1H-吡咯啉[1,2-a][1,5-]苯并二氮杂(艹卓)的晶体结构.单斜晶系,空间群P21/c,a=1.3235(5)nm,b=1.7142(6)nm,c=1.6204(6)nm,β=100.49(3)埃琙=4,最终偏离因子R=0.062,Rw=0.075.晶体结构测定结果表明分子中二氮杂(艹卓)七元环采取船式构象,动力学模拟退火计算结果的最低能量构象为椅式,两者的能量差不大,表明这种船式←→椅式的变化是非常容易发生的.     

一个取代的三环1,5-苯并二氮杂卓的晶体结构和构 象分析2

用单晶X射线衍射方法测定了6-苯甲酰基-5-(邻氯苯基)-2,3,3a,4,5,6-六氢-3a-苯基-(1,2,3-三乙酸乙酯基)-1H-吡咯啉[1,2-a][1,5-]苯并二氮杂卓的晶体结构。单斜晶系,空间群P2~1/c,a=1.3235(5)nm,b=1.7142(6)nm,c=1.6204(6)nm,β=100.49(3)°,Z=4,最终偏离因子R=0.062,R~w=0.075。晶体结构测定结果表明分子中二氮杂卓七元环采取船式构象,动力学模拟退火计算结果的最低能量构象为椅式,两者的能量差不大,表明这种船式<－>椅式的变化是非常容易发生的。     

一个取代的三环1,5-苯并二氮杂卓的晶体结构和构 象分析2

用单晶X射线衍射方法测定了6-苯甲酰基-5-(邻氯苯基)-2,3,3a,4,5,6-六氢-3a-苯基-(1,2,3-三乙酸乙酯基)-1H-吡咯啉[1,2-a][1,5-]苯并二氮杂卓的晶体结构。单斜晶系,空间群P2~1/c,a=1.3235(5)nm,b=1.7142(6)nm,c=1.6204(6)nm,β=100.49(3)°,Z=4,最终偏离因子R=0.062,R~w=0.075。晶体结构测定结果表明分子中二氮杂卓七元环采取船式构象,动力学模拟退火计算结果的最低能量构象为椅式,两者的能量差不大,表明这种船式<－>椅式的变化是非常容易发生的。     

3-甲基-1a-(4-甲氧基苯基)-1,1-二氯-1,1a,2,3-四氢-吖丙啶并[2,1-d][1,5]苯并硫氮杂的合成和晶体结构

通过2-甲基-4-(4-甲氧基苯基)-2,3-二氢-1,5-苯并硫氮杂与二氯卡宾的[2 1]环加成反应制备了标题化合物,用X射线单晶衍射测定了其晶体结构.分子式C_(18)H_(17)Cl_2NOS,分子量366.30,晶体属正交晶系,空间群P_(bca),晶胞参数:a=1.2246(3)nm,b=1.5219(4)nm,c=1.9272(9)nm,V=3.592(2)nm~3,Z=8,D_c=1.355g·cm~(-3).位于中心的1,5-硫氮杂环为扭曲的类船式构象,船头与苯环并合,船底与吖丙啶环并合.     

二氢和四氢-2-甲基-4-芳基(1,5)苯并硫氮杂的构象分析(Ⅰ)

本文研究了2-甲基-4-芳基(1,5)苯并硫氮杂的光谱和构象分析,确立了二氢化物具有类船式构象。形成二氢化物的成环反应是高度立体选择性的,分子内杂环并联的苯环和取代的芳环的平面夹角约为50度,但4位的芳环仍能和杂环并联的苯环发生明显的共轭效应,氮原子在这里起着关键作用。二氢化物用硼氢化钠还原,得到的四氢化物的构象是扭船式的,也是稳定的,这显然是由这个体系的结构所决定的。还原反应是立体专一性的。     

三组分串联反应一锅合成多环稠合的1,5-苯并二氮杂䓬化合物

以取代的邻苯二胺、1,3-环戊二酮或1,3-环己二酮(5,5-二甲基-1,3-环己二酮)、2,3-二羰基化合物为原料,无水乙醇为溶剂,对甲苯磺酸为催化剂,经2~5 h串联反应一锅合成43种新颖的1,5-苯并二氮杂?化合物,产率最高可达95%.该反应序列首先通过两次的亲核加成-脱水反应过程,形成分子内亚胺和烯胺结构的活性中间体,然后再经分子内的碳碳偶联环合-质子转移等过程,生成多环稠合的1,5-苯并二氮杂?目标化合物,实现了在一个反应体系中形成一个二氮杂七元环和四个新化学键(两个C—N,一个C=C,一个C—C).该方法操作简单,反应便捷,对环境友好,产率高,为1,5-苯并二氮杂?化合物的合成提供绿色环保,高效简便的合成思路.     

新型1,5-苯并二氮杂卓衍生物的结构与抑菌活性的理论分析

采用密度泛函理论(DFT)方法,在B3LYP/6-31G(d,p)水平上对一系列新型1,5-苯并二氮杂卓衍生物进行了几何结构全优化和理论计算研究,得到分子的几何结构、NPA电荷、红外振动光谱及轨道贡献。研究结果表明:1,5-苯并二氮杂卓分子的七元环是扭船式构型;分子不同位置连接不同的取代基,对分子的电荷分布有一定影响;红外光谱理论计算结果与实验结果相吻合。通过探讨前线轨道与抑菌活性的关系发现,所研究的杂卓分子对不同菌株的抑菌活性具有选择性和特异性,其中分子中的N(11)和C=N可能分别是所合成的该类化合物与细菌(枯草杆菌)和真菌(白色念珠菌和新型隐球菌)发生作用的主要活性部位。     

Synthesis, structure, and transannular pi-pi interaction of three- and four-layered [3.3]paracyclophanes

The synthesis of three- and four-layered [3.3]paracyclophanes ([3.3]PCPs) 3-5 has been accomplished by utilizing the (p-ethylbenzenesulfonyl)methyl isocyanide (EbsMIC) method. The structures of the three- to four-layered [3.3]PCPs 3- 5 and their diones 8, 10, and 11 have been elucidated based on the (1)H NMR spectra and finally by X-ray structural analysis. In the three-layered [3.3]PCP-dione 8, the trimethylene bridges of the [3.3]PCP unit assume a chair conformation similar to that of 2, while the [3.3]PCP-2,11-dione unit assumes a boat conformation different from that of [3.3]PCP-dione 1 with a chair conformation. On the other hand, the two [3.3]PCP units in three-layered [3.3]PCP 3 both assume a boat conformation. In the four-layered [3.3]PCP-dione 10, the two outer [3.3]PCP units assume a boat conformation while the inner dione unit has a chair conformation. The trimethylene bridges in the four-layered [3.3]PCP 4 are highly disordered even at -150 degrees C. All the outer benzene rings are distorted into a boat form while the inner ones are distorted into a twist form. In the electronic spectra, bathochromic shift and hyperchromic effect are observed, but the magnitude decreases with an increase in the number of layers and the spectra become structureless. In the charge-transfer (CT) bands of the three- to four-layered [3.3]PCPs 3- 5 with tetracyanoethylene (TCNE), two absorption maxima (lambda(max)) are observed. The effect of an increase in the layers becomes significant, and the changes in the longest wavelength lambda(max) values from two to three and three to four are ca. 60 and 50 nm, respectively. By comparison of the stereoisomeric four-layered [3.3]PCPs 4 (meso) and 5 (racemic), the helical arrangement of the trimethylene bridges of 5 shows a more efficient transannular pi-electronic interaction. In the three- to four-layered [3.3]PCP-diones, a magnitude of the CT interaction almost comparable to that of [3.3]PCP 2 was observed, and this indicates that the -CH(2)COCH(2)- bridges inhibit the CT interaction and that this tendency is supported by the calculated HOMO energy levels and observed oxidation potentials. Three- and four-layered [3.3]PCPs 3- 5 show reversible redox processes, and 4 and 5 show an electron-donating ability almost comparable to that of [3 6]CP. Very good correlation between the lambda(max) of the CT bands with TCNE and the oxidation potentials is observed.     

Synthesis, structure and spectroscopic properties of calix[4]phloroglucinarene dodecamethyl ether and its trifluoroacetic acid complex

The action of trifluoroacetic acid (TFA) on 2,4,6-trimethoxybenzyl alcohol 3 affords the title tetrameric compound in high yield as a maroon TFA complex, 4; trituration of which with acetone gives the free, colorless, calix[4]phloroglucinarene (5) that can also be directly isolated by treating the reaction mixture with base. The novelty of compounds 4 and 5 is that they possess four additional methoxy groups, which occupy the cavity of the known calix[4]resorcinarene octamethyl ether (2). Ultraviolet-visible spectroscopic analysis shows that TFA-complex 4 exhibits transannular charge-transfer interactions between the opposite aromatic rings. The (1)H-NMR spectrum of the TFA-complex 4 does not change over a wide temperature range, strongly suggesting that it adopts a saddle (1,3-alternate) structure. The conformation of the free phloroglucinarene 5 is temperature-dependent, as determined by variable temperature (1)H NMR spectroscopy. Tetramer 5 adopts a partial cone conformation at low temperatures, but at elevated temperatures is similar to that of the TFA complex 4 (saddle). Tetramer 5 is conformationally mobile at ambient temperature, but generally has a flattened cone (boat) conformation. The ΔG(≠) for inversion in 5 between partial cone and boat conformation is 12.5 Kcal mol(-1), while that between boat and saddle conformation is 14.3 Kcal mol(-1). Conformational changes are also dependant on pH.     

Crystal and molecular structure of 6,6-dimethyl-cis-2,4-diphenyl-3-aza-7-oxabicyclo[3.3.1]nonan-9-one

A method is presented for synthesizing 6,6-dimethyl-2,4-diphenyl-3-aza-7-oxabicyclo[3.3.1]nonan-9-one. The x-ray structure shows that the compound in the crystal exists in the chair-boat conformation with the piperidine ring in the boat form. The two phenyl substituents in the 2- and 4-positions are responsible for such a conformation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1400–1402, October, 1990.     

1,5-Diazabicyclo[3.1.0]hexanes and 1,6-diazabicyclo[4.1.0]heptanes: a new method for the synthesis,quantum-chemical calculations,and X-ray diffraction study

A new method was developed for the synthesis of 6-substituted 1,5-diazabicyclo[3.1.0]hexanes and 7-substituted 1,6-diazabicyclo[4.1.0]heptanes by condensation of N-monohalotrimethylene- and N-monohalotetramethylenediamines with carbonyl compounds in the presence of bases. X-ray diffraction studies and quantum-chemical B3LYP/6-31G* calculations demonstrated that the conformations of the resulting bicyclic systems are stabilized by stereoelectronic interactions. As a result, a boat conformation prevails in 1,5-diazabicyclo[3.1.0]hexanes, whereas the energies of chair, half-chair, and boat conformations of 1,6-diazabicyclo[4.1.0]heptanes are equalized.     

Molecular structure of 1,5-diazabicyclo[3.1.0]hexane as determined by gas electron diffraction and quantum-chemical calculations

The equilibrium molecular structure and conformation of 1,5-diazabicyclo[3.1.0]hexane (DABH) has been studied by the gas-phase electron-diffraction method at 20 degrees C and quantum-chemical calculations. Three possible conformations of DABH were considered: boat, chair, and twist. According to the experimental and theoretical results, DABH exists exclusively as a boat conformation of C s symmetry at the temperature of the experiment. The MP2 calculations predict the stable chair and twist conformations to be 3.8 and 49.5 kcal mol(-1) above the boat form, respectively. The most important semi-experimental geometrical parameters of DABH (r(e), A and angle)e), deg) are (N1-N5) = 1.506(13), (N1-C6) = 1.442(2), (N1-C2) = 1.469(4), (C2-C3) = 1.524(7), (C6-N1-C2) = 114.8(8), (N5-N1-C2) = 107.7(4), (N1-C2-C3) = 106.5(9), and (C2-C3-C4) = 104.0(10). The natural bond orbital (NBO) analysis has shown that the most important stabilization factor in the boat conformation is the n(N) --> sigma*(C-C) anomeric effect. The geometry calculations and NBO analysis have been performed also for the bicyclohexane molecule.     

Synthesis of New Calix[4]arenes Functionalizated by Acetylhydrazide Groups

A series of new calix[4]phenols, calix[4]resorcinols and calix[4]pyrogallols with acetylhydrazide substitutes has been␣synthesized with high yields by hydrazinolysis of ester group containing calix[4]arenes. The synthesized calix[4]phenols adopt the cone conformation while the calix[4]resorcinol and calix[4]pyrogallol derivatives prefer the boat conformation. The amide fragment of the hydrazide groups predominantly exists in the trans-conformation. The binding ability of synthesized calix[4]arenes toward transition and alkali metals by solvent extraction has been investigated.     

Synthesis and Crystal Structure of 5-Cyclopropyl- 10-（4-fluorophenyl）-7,7-dimethyl-7,8-dihydro-5H- indeno[1,2-b]quinoline-9,11（6H,10H）-dione

The title compound 5-cyclopropyl-10-(4-fluorophenyl)-7,7-dimethyl-7,8-dihydro- 5H-indeno[1,2-b]quinolne-9,11(6H,10H)-dione was obtained by the reaction of 4-fluorobenzal- dehyde, 2H-indene-1,3-dione and 3-(cyclopropylamino)-5,5-dimethylcyclohex-2-enone in the presence of acetic acid under microwave irradiation. Its structure was confirmed by IR and 1H- NMR spectra. The crystal is of monoclinic, space group P21/c with a = 14.138(3), b = 8.952(2), c = 17.140(3) , β = 102.253(3)o, C27H24FNO2, Mr = 413.47, Z = 4, V = 2119.9(8) 3, Dc = 1.296 g/cm3, μ(MoKα) = 0.087 mm-1, F(000) = 872, the final R = 0.0425 and wR = 0.0905 for 2336 observed reflections (I > 2σ(I)). X-ray analysis revealed that the pyridine ring adopts a boat conformation and the six-membered ring fused with it assumes a twist boat conformation.     

Synthesis and structure characterization of unsymmetrical oxacalix[2]benzene[2]pyrazines

The synthesis of two unsymmetrically linked oxacalix[2]benzene[2]pyrazines (1 and 2) is described. X-ray single crystal structure analysis revealed a highly distorted 1,3-alternate conformation of compound 1 (containing ortho- and meta-diphenol components) and a distorted boat conformation of compound 2 (containing meta- and para-diphenol components). Oxacalix[2]benzene[2]pyrazine containing both ortho- and para-diphenol components was not obtained via similar synthetic strategy.