Photochemical formation of [4.4.4](1,3,5)cyclophanes from 1,3,5-tris(3-phenylpropenoyl)benzenes

Irradiation of 1,3,5-tris(3-phenylpropenoyl)benzene (1a) yields in solution a dimer 2a by a threefold head-to-head/anti [2π+2π]cycloaddition. The stereochemistry of this [4.4.4](1,3,5)cyclophane was determined by ¹H and ¹³C NMR studies including NOE measurements and a calculation of the AA′MM′ spin pattern of the methine protons. In contrast to the solution photochemistry, which is presumably controlled by the arrangement of an excimer, the irradiation in the crystalline state leads by a topochemical control to a dimer 3a, which contains a single four-membered ring.     

离子色谱法测定1,3,5-三(3-二甲基氨丙基)六氢三嗪含量

建立了环状有机多胺类化合物1,3,5-三(3-二甲基氨丙基)六氢三嗪(PC41)的离子色谱测定法。研究表明,采用Ionpac CS12A阳离子交换柱,抑制电导模式,以25 mmol/L硫酸溶液为淋洗液,可对1,3,5-三(3-二甲基氨丙基)六氢三嗪进行定量测定。多胺类化合物在抑制电导下为非线性响应,故采用二次抛物线方法定量,线性范围为0~17.84 mg/L,线性方程为y=–0.001 8x2+0.231 3x+0.011 5,相关系数为0.999 8,测量结果的相对标准偏差小于1%(n=5),3水平加标回收率为99.3%~100.2%。该方法操作简单,测定结果准确可靠,可用于测定合成聚亚胺酯原料1,3,5-三(3-二甲基氨丙基)六氢三嗪的含量。     

Conformational analysis of 12,12,21,21-tetradeuterio-1,4-dioxa-[4.3.3](1,3,5)Cyclophane

All possible three conformers (chair-chair, chair-boat, and boat-boat) of the title compound were detected by ¹H NMR spectrum below 223K(−50°C).     

Trisubstituted 1,3,5-Triazines. 6. Synthesis of 2,4,6-Tris(acetonyl)-1,3,5-triazine

Acylation of 2,4,6-tris(tert-butoxycarbonylmethyl)-1,3,5-triazine with acetic anhydride in the presence of lithium hydride with subsequent removal of the tert-butoxycarbonyl groups with trifluoroacetic acid leads to 2,4,6-tris(acetonyl)-1,3,5-triazine, the cyclic analog of -cyanoacetone. The special spectral features of this compound compared with triazines obtained previously are discussed.     

Variable ion selectivity in [N.3.3](1,3,5)crownophanes: the "breathing" process

[reaction: see text] A series of dithia[n.3.3](1.3.5)crownophanes were synthesized by cesium carbonate-assisted intramolecular cyclization reactions in 10-31% yields. Their complexation behavior exhibits an unusual ion-selectivity preference due to the presence of a "breathing" process of the dithia[3.3]metacyclophane moiety, which indirectly controls the ion selectivity through the adjustment of the cavity size of the crown unit. This breathing mechanism is also supported by observation made in X-ray crystallographic analysis.     

Condensed tetrazolo-1,3,5-triazines. 4. Synthesis of salts of 5-aminotetrazolo[1,5-a]-1,3,5-triazin-7-one

2-Amino-4-azido-1,3,5-triazin-6(1H)-ones were synthesized by successive substitution of the trinitromethyl groups in 2-amino-4,6-bis(trinitromethyl)-1,3,5-triazines under the influence of azide and nitrite ions. Interaction of 2-amino-4-azido-1,3,5-triazin-6(1H)-ones with bases led to the azido-tetrazole tautomeric conversion give salts of 5-aminotetrazolo[1,5-a]-1,3,5-triazin-7-one. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1211–1219, August, 2006.     

1,3,5-三硝基-六氢化-1,3,5-三嗪-2(1H)-酮(Keto-RDX)新法合成、晶体结构和热性能研究

研究了1,3,5-三硝基-六氢化-1,3,5-三嗪-2(1H)-酮(Keto-RDX)的合成新方法,以乌洛托品和硝基胍为原料,通过Mannich反应得到2-硝亚胺基-六氢化-1,3,5-三嗪盐酸盐(NIHT·HCl),用HNO3/AC2O硝化可得Keto-RDX,并采用核磁共振、红外、质谱以及元素分析等进行了结构表征.培养了Keto-RDX单晶,晶体结构解析表明:晶体属于正交晶系,空间群Pnma,晶胞参数a=1.0057(17)nm,b=1.3483(2)nm,c=0.5982(10)nm,V=0.8112(2)nm3,Z=4,Dc=1.933 g/cm3,μ=0.188 mm-1,F(000)=480.差示扫描量热(DSC)法和热失重(TG/DTG)法分析表明,Keto-RDX分解峰温为211.4℃(DSC),在185.00～202.79℃为固相分解阶段,峰温为198.61℃,质量损失为21.45%,在202.79～230.00℃为液相分解阶段,质量损失为77.83%,峰温为213.78℃,热稳定性较RDX差.     

Conformation of dithia[3.3]- and [2.2] azuleno(2,6)pyridinophanes

Four azuleno(2,6)pyridinophanes (1–4) were synthesized and their conformations were found by NMR spectroscopy to be very similar to those of the corresponding azulenometacyclophanes. A transverse conformational change was observed for [2.2](5,7)azuleno(2,6)pyridinophane.     

Triply bridged (1,3,5) cyclophanes from cystine and lanthionine linkers—a comparison

The condensation of benzene 1,3,5-tricarbonylchloride with cystine-di-Me [H₂N-CH(COOMe)-CH₂-S-S-CH₂-CH(COOMe)-NH₂] yielded triply bridged (1,3,5) cyclophane 1, which was shown by detailed spectral studies and molecular orbital calculations to have a D₃ symmetry with conformationally identical linkers and a spherical topology. In sharp contrast, the (1,3,5) cyclophane 2 from the rarely studied lanthionine di-Me [H₂N-CH(COOMe)-CH₂-S-CH₂-CH(COOMe)-NH₂], showed only a equatorial twofold symmetry. This work highlights the special properties of the -S-S- bridge in cystine, which makes it an exceptional synthon in nature and organic synthesis.     

Cationic cyclocodimerization. 2. Syntheses of [3.3](1,4)naphthalenophane and [3.3]paracyclo(1,4)naphthalenophane derivatives

1,3-bis(4-vinylnaphthyl)propane and 1-(4-vinylnaphthyl)-3-($\text{p}$-vinylphenyl)propane, were cyclocodimerized with indene to afford indenyl-substituted [3.3](1,4)naphthalenophanes and [3.3]paracyclo(1,4)naphthalenophanes.     

Trisubstituted 1,3,5-Triazines. 5. Reaction of 2,4,6-Tris[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine with Nucleophiles

The reaction of 2,4,6-tris[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine with ammonia, amines, and hydrazine has been studied. It was possible to substitute one of the di(tert-butoxycarbonyl)nitromethyl groups in this compound in the presence of ammonia, primary aliphatic amines, dimethylamine, and morpholine. The reaction with hydrazine leads to both mono- and disubstituted products. A double dealkoxylation occurs in the presence of diethylamine to give the bis(dimethylammonium) salt of 2,4-bis(tert-butoxycarbonylnitromethyl)-6-[di(tert-butoxycarbonyl)nitromethyl]-1,3,5-triazine.     

Synthesis and photophysical properties of [3.3](3,9)carbazolophanes

Syn- And anti-[3.3](3,9)carbazolophanes, which are suitable model compounds for sandwich and partial-overlap excimers, respectively, have been synthesized and characterized; the structures of both singlet and triplet carbazole excimer have been described.     

Pd-catalyzed C-N coupling of primary (het)arylamines with 5-substituted 3-chloro-4H-1,2,6-thiadiazin-4-ones

The Buchwald-Hartwig Pd-catalyzed C-N coupling reaction of 5-substituted 3-chloro-4H-1,2,6-thiadiazin-4-ones with primary (het)arylamines is described, affording twenty new 3,5-disubstituted 4H-1,2,6-thiadiazin-4-ones in 56–99% yield. The protocol enables the mild preparation of difficult to access 3,5-dianilino-1,2,6-4H-thiadiazin-4-ones. The reaction scope and limitations are discussed.     

Synthesis of [n]- and [n.n]cyclophanes by using Suzuki-Miyaura coupling

Reaction of the bis-9-BBN adduct of several dienes with 1,3-dibromobenzene via Suzuki coupling leads to a series of [n]metacyclophanes ranging in size from 10 to 17 atom members. In each case, two carbon-carbon bonds are formed in one reaction vessel. However, when the bis-9-BBN adduct of 1,5-hexadiene is coupled with a variety of aryl dihalides, larger [n.n]cyclophanes were formed in preference to the [n]cyclophanes. Four carbon-carbon bonds are formed in this instance. Single-crystal X-ray analyses of these [n.n]cyclophanes reveal interestingly shaped molecules with large cavities.     

Photochemical study of [3(3)](1,3,5)cyclophane and emission spectral properties of [3n]cyclophanes (n = 2-6)

Thephotochemical reaction of [3(3)](1,3,5)cyclophane 2, which is a photoprecursor for the formation of propella[3(3)]prismane 18, was studied using a sterilizing lamp (254 nm). Upon photolysis in dry and wet CH2Cl2 or MeOH in the presence of 2 mol/L aqueous HCl solution, the cyclophane 2 afforded novel cage compounds comprised of new skeletons, tetracyclo[6.3.1.0.(2,7)0(4,11)]dodeca-5,9-diene 43, hexacyclo[6.4.0.0.(2,6)0.(4,11)0.(5,10)0(9,12)]dodecane 44, and pentacyclo[6.4.0.0.(2,6)0.(4,11)0(5,10)]dodecane 45. All of these products were confirmed by the X-ray structural analyses. A possible mechanism for the formation of these photoproducts via the hexaprismane derivative 18 is proposed. The photophysical properties in the excited state of the [3n]cyclophanes ([3n]CP, n = 2-6) were investigated by measuring the emission spectra and determining the quantum yields and lifetimes of the fluorescence. All [3n]CPs show excimeric fluorescence without a monomeric one. The lifetime of the excimer fluorescence becomes gradually longer with the increasing number of the trimethylene bridges. The [3n]CPs also shows excimeric phosphorescence spectra without vibrational structures for n = 2, 4, and 5, while phosphorescence is absent for n = 3 and 6. With an increase in symmetry of the benzene skeleton in the [3(3)]- and [3(6)]CPs, the probability of the radiation (phosphorescence) process from the lowest triplet state may drastically decrease.     

2,4,6-三萘基-1,3,5-三嗪的合成与光谱行为

本文通过Suzuki偶联反应高效合成了两种三萘基三嗪化合物,即2,4,6-三(1-萘基)-1,3,5-三嗪(T1NT)和2,4,6-三(2-萘基)-1,3,5-三嗪(T2NT). 考察了介质的极性、温度以及THF-H₂O二元溶剂体系中的溶解性等因素对它们吸收和发射光谱行为的影响.研究发现, 由于T1NT比T2NT具有更好的分子平面性,其激发态下分子内电荷转移的程度较大,导致其在溶液中吸收光谱、发射光谱比T2NT呈现显著红移.冻结态下,分子平面性较差的T2NT显示出较短波长的发光.     

Nucleophilic Substitution Reactions of 2,4,6-Tris(trinitromethyl)-1,3,5-triazine. 3. Reaction of 2,4,6-Tris(trinitromethyl)-1,3,5-triazine with Azides and Hydrazine

As a result of nucleophilic substitution of the trinitromethyl groups in 2,4,6-tris(trinitromethyl)-1,3,5-triazine, the corresponding monoazido and diazido derivatives have been synthesized. The reaction of the starting triazine with hydrazine acetate in the presence of trifluoroacetic acid leads to 1-acetyl-2,2-bis[4,6-bis(trinitromethyl)-1,3,5-triazin-2-yl]hydrazine.     

Intramolecular excimer emission of triply bridged [3.3.N](3,6,9)carbazolophanes

The photophysical properties of a series of triply bridged [3.3.n](3,6,9)carbazolophanes ([3.3.n]Cz, n = 3, 4, 5, 6) were studied as a model compound for a fully overlapped carbazole excimer. In these [3.3.n]Cz molecules, a plane angle of the two carbazole moieties changed systematically from nearly parallel to oblique, with increases in the length of the methylene chain n bridging at the 9-position of each carbazole ring. Absorption bands of [3.3.n]Cz showed the blue-shift and the splitting for (1)L(a) <-- (1)A and (1)L(b) <-- (1)A transition bands of the reference carbazole monomer, respectively. These spectral changes in [3.3.n]Cz were explained by Kasha's molecular exciton theory with the distance r and dihedral angle theta between the carbazole moieties in the ground state. In both liquid and glass matrixes, [3.3.n]Cz showed intramolecular excimer emission. The emission peak wavelength changed from 409 nm (n = 6) to 480 nm (n = 3) depending on r in the ground state. The dependence of the peak wavelength on r clearly showed that relative configurations of carbazole moieties in the ground state were preserved even in the excimer states. The smaller radiative rate of the excimer emission than the reference monomer was explained by the dimer symmetry of [3.3.n]Cz.