Selective synthesis of meso-naphthylporphyrins

A series of novel meso-(8-substituted naphth-1-yl)porphyrins has been synthesized creating derivatives with a tight recognition environment above the porphyrin plane. The selective synthesis of single atropisomers is discussed. Condensation of bisnaphthaldehyde 12 with phenyldipyrromethane unexpectedly led to selective synthesis of the alpha,alpha-5,10-bridged isomer 14. A mechanism is proposed for this unusual scrambling, and alternative syntheses of alpha,alpha-5,15-bisnaphthylporphyrins are described. Synthesis of 5,15-analogues can be achieved by employing (pentafluorophenyl)dipyrromethane or via presynthesis of a bis(dipyrromethane) derivative 22 (from bisnaphthaldehyde 12) and subsequent condensation with benzaldehyde.     

The Heck reaction for porphyrin functionalisation: synthesis of meso-alkenyl monoporphyrins and palladium-catalysed formation of unprecedented meso-beta ethene-linked diporphyrins

Palladium-catalysed coupling of the vinyl derivatives methyl acrylate, styrene and acrylonitrile with 5-bromo-10,15,20-triphenylporphyrin (MTriPPBr; M = 2H, Ni, Zn) and 5,15-dibromo-10,20-bis(3,5-di-tert-butylphenyl)porphyrin (MDAPBr(2)) produced a series of mono- and disubstituted alkenylporphyrins, thus demonstrating the applicability of meso-haloporphyrins in Heck-type reactions. The same technique was also applied to meso-ethenylporphyrins and simple aryl halides, with mixed results. Only meso-vinyl nickel(ii) porphyrins showed any reactivity under our conditions. A mixture of 1,1- and 1,2-disubstitution across the alkene was observed for 5-vinyl-10,15,20-triphenylporphyrinatonickel(ii) (meso-vinylNiTriPP), whereas 5-vinyl-10,20-bis(3,5-di-t-butylphenyl)porphyrinatonickel(ii) (meso-vinylNiDAP) produced a mixture of meso-1,1-, meso-1,2- and, surprisingly, beta-1,2-disubstituted Heck products. Coupling meso-vinylNiDAP with MTriPPBr under similar Heck conditions led unexpectedly to transbeta-meso-NiDAP-ethene-MTriPP dyads, affording the first members of a new class of alkenyl-linked diporphyrins. A mechanism for the unusual meso to beta rearrangement is discussed. The electronic absorption spectra of the dyads have a red-shifted shoulder on the Soret (B) band, which is evidence of a moderate degree of electronic interaction between the porphyrins via the ethenyl bridge.     

2-甲基-3-芳基烯丙基三苯基溴代鏻的合成

取代苯甲醛经醇醛缩合、硼氢化还原、溴代反应和成盐反应合成了２-甲基-３-间硝基苯基烯丙基三苯基溴化特和２-甲基-３-对硝基苯基烯丙基三苯基溴化鏻两个化合物,收率分别达８６．４％和６９．０％。结构经ＩＲ,1ＨＮＭＰ确证。     

The synthesis and studies towards the self-replication of bis(capped porphyrins)

Connecting two facially-protected porphyrins was expected to lead to an equal mixture of laterally-bridged doubly-protected bis-porphyrins; one in which the two porphyrin units were protected on the same face (syn) and one with the two prophyrin units protected on opposite faces (anti). Addition of a co-factor (bidentate ligand) was expected to lead predominantly to the syn-bis-porphyrin by a templated self-replication process. This concept was explored using Baldwin's capped porphyrin. Bis(capped porphyrins) were synthesised in several steps starting from zinc(II) capped porphyrin 2. Nitration of 2 followed by reduction and photo-oxidation yields a mixture of zinc(II) porphyrindiones 7 and 8 that can separated by HPLC. The condensation of 2 molar eq. of zinc(II) porphyrin-7,8-dione 8 with 1,2,4,5-benzenetetramine leads to the formation of a 1:1 mixture of syn- and anti-dizinc(II) bis(7,8-capped porphyrins), 11 and 12, respectively, that have almost identical spectroscopic properties. These two geometric isomers were distinguished by significant differences in their molecular recognition properties. Likewise the syn- and anti-dizinc(II) bis(2,3-capped porphyrins), 9 and 10, respectively, are synthesised from the related zinc(II) capped porphyrin-2,3-dione 7, and were also identified using molecular recognition studies. The molecular recognition properties of these bis(capped porphyrins) were utilised in studies of self-replicating porphyrin systems. The results show that tetraazaanthraceno-bis-porphyrins 9-12 can catalyse their own formation but self-replication was not observed. These results highlight the potential that these interesting hosts have as templates in supramolecular chemistry, synthesis and catalysis.     

meso-5,10,15,20-四（取代2-噻吩基）卟啉及其配合物的合成与表征

用混合溶剂法合成了中位噻吩基取代的卟啉化合物：meso-四(2-噻吩基)卟啉 ，meso-四(4-溴-2-噻吩基)卟啉和meso-四(3-甲基-2-噻吩基)卟啉，产率达到36． 5％-39．3％，考察了溶剂的配比、反应温度、反应时间等因素对反应的影响，其 最佳反应条件为：溶剂配比：丙酸：乙酸：硝基苯：2：2(or3)：1；反应温度： 130~140t；反应时间：50-60min．研究了利用固相合成法合成上述卟啉化合物与过 渡金属盐形成配合物的配位反应，在40℃利用固相合成法合成了卟啉化合物与 Fe2' Fe~3+，CO~2+，Ni~2+，Mn~2+等过渡金属离子形成的配合物，产率为81．1 ％~87．6％．利用元素分析，UV-vis，m，'HNMR， HRMS对卟啉化合物及其配合物 进行了表征，利用TG-DTA研究了它们的热稳定性，利用EPR研究了它们的顺磁性．     

The synthesis and proton nuclear magnetic resonance study of some nitro- and amino-unsymmetrically meta-substituted tetraphenylporphyrins

Procedures for the synthesis of new partially-substituted mesotetraphenylporphyrins (TPP's) are described. The 5-(3-nitrophenyl)-10,15,20-triphenylporphyrin is the primary product from a 1:2:3 molar ratio of m-nitrobenzaldehyde, benzaldehyde and pyrrole. The crude reaction product also contained TPP, 5,10-bis-(3-nitrophenyl)-15,20-diphenylporphyrin, 5,15-bis(3-nitrophenyl)-10,20-diphenylporphyrin, and 5,10,15-tris-(3-nitrophenyl)-20-phenylporphyrin. The crude mixture of m-nitrophenylporphyrins was reduced to a mixture of the corresponding amino derivatives, which was separated into TPP, 5-(3-aminophenyl)-10,15,20-triphenylporphyrin, 5,10-bis(3-aminophenyl)-15,20-diphenylporphyrin, and 5,15-bis(3-aminophenyl)-10,20-diphenylporphyrin. The products were characterized by uv-visible and ir spectrophotometry, and by high resolution nmr spectroscopy and mass spectroscopy.     

The mixed-aldehyde synthesis of difunctional tetraarylporphyrins

The synthesis is reported of nine unsymmetrical, meso-substituted porphyrins. Among the compounds prepared are the following 5-(R)-10,15,20-tri-p-tolylporphyrins; R = 2,6-dinitrophenyl, 4-hydroxy-3-ethoxy-phenyl, 4-hydroxy-3-methoxy-5-nitrophenyl, 5-hydroxy-2-nitrophenyl and 4-hydroxy-3-nitrophenyl. Other porphyrins reported include 5-(2-(1-butoxy)phenyl)-15-(2-nitrophenyl)-10-15-di-p-tolylporphyrin and the two 5-(R)-10-15,20-tripropylporphyrins in which R = 2-nitrophenyl and 2-hydroxyphenyl. The disubstituted porphyrins offer a rational route to the synthesis of difunctional “tailed-porphyrins”.     

Treatment of dimethyl (+)-L-tartrate with sulfur tetrafluoride

Treatment of dimethyl (+)-L-tartrate (I) with sulfur tetrafluoride results in the formation of an intermediate, 2-fluoro-1,2-bis(methoxycarbonyl)ethyl fluorosulfite (II), which under the action of hydrogen fluoride, present in the reaction mixture, is converted into dimethyl (?)(2S:3S)-2-fluoro-3-hydroxysuccinate (III). The reaction of the latter with SF₄ leads to dimethyl meso-2,3-difluorosuccinate (IV). The structure and configurations of the compounds obtained were established by ¹H and ¹⁹F NMR. Treatment of dimethyl (+)-L-tartrate (I) with sulfur tetrafluoride in the presence of excessive hydrogen fluoride gave dimethyl meso-2,3-difluorosuccinate in 96% yield.     

3-Cyclobutenyl-1,2-dione-substituted porphyrins. A general and efficient entry to porphyrin-quinone and quinone-porphyrin-quinone architectures

A new and efficient synthesis of meso-linked porphyrin-quinone dyads and quinone-porphyrin-quinone triads has been developed via the intermediacy of porphyrins bearing 3-cyclobutenyl-1,2-dione and 3-(1-ethenyl)cyclobutenyl-1,2-dione substituents at one or two nonadjacent meso-positions. The free-base porphyrins 5-bromo-10,20-diphenylporphyrin and 5,15-dibromo-10,20-diphenylporphyrin undergo facile palladium-catalyzed Stille coupling with 3-isopropoxy-2-tri-n-butylstannyl-cyclobutene-1,2-dione to produce the corresponding mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins in good yields. In contrast, the zinc bromoporphyrins reacted with the same tin reagent only slowly and with the formation of side products. The free-base bromoporphyrins also were coupled with tri-n-butylvinyltin to afford vinylporphyrins in very good yields. 5,15-Diphenyl-10-vinylporphyrin was converted into trans-bromovinylporphyrin, which underwent facile Stille coupling with 3-isopropoxy-2-tri-n-butylstannylcyclobutene-1,2-dione to afford the vinylogous 3-cyclobutenyl-1,2-dione-substituted porphyrin. The molecular structure of 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n) was determined by X-ray crystallography. Although the data revealed a fairly large dihedral angle between the cyclobutenedione and the porphyrin rings (57 degrees), the UV-vis spectra of both the mono- and bis(3-cyclobutenyl-1,2-dione)-substituted porphyrins showed B- and Q-band red shifts indicative of strong electronic coupling between the porphyrin and cyclobutenedione chromophores in solution. Introduction of a double bond between the cyclobutenedione and porphyrin rings resulted in a significant red shift of both the B- and Q-bands compared to those of the nonvinylogous system. All porphyrinic cyclobutenediones were metalated with zinc and then, using established cyclobutenedione chemistry, converted into a variety of porphyrin-quinones in excellent yields with aryllithium and vinylic Grignard reagents. From the mono(3-cyclobutenyl-1,2-dione)-substituted porphyrin, 7, a variety of directly linked monoquinone-porphyrin dyads were easily synthesized. Substituents could also be introduced at the free meso-position of 7 by bromination followed by palladium-catalyzed cross-coupling reactions, and additional porphyrinic monoquinones were then prepared from these starting materials. The vinylogous squarylporphyrin was converted into a double bond linked porphyrin-quinone via reaction with phenyllithium followed by thermal rearrangement and oxidation. As a result of the hindered rotation around the C-C bond between the porphyrin and the quinone, pairs of stable, separable, and thermally interconvertable atropisomers of porphyrin-quinones were obtained from 5,15-bis(3-cyclobutenyl-1,2-dione)-10,20-diphenylporphyrin(Z n). The structure of one of the atropisomers was determined by X-ray crystallography.     

meso‐3,5‐Bis(trifluoromethyl)phenyl‐Substituted Expanded Porphyrins: Synthesis,Characterization, and Optical,Electrochemical, and Photophysical Properties

Trifluoroacetic acid‐catalyzed condensation of pyrrole with electron‐deficient and sterically hindered 3,5‐bis(trifluoromethyl)benzaldehyde results in the unexpected production of a series of meso‐3,5‐bis(trifluoromethyl)phenyl‐substituted expanded porphyrins including [22]sapphyrin 2 , N‐fused [22]pentaphyrin 3 , [26]hexaphyrin 4 , and intact [32]heptaphyrin 5 together with the conventional 5,10,15,20‐tetrakis(3,5‐bis(trifluoromethyl)phenyl)porphyrin 1 . These expanded porphyrins are characterized by mass spectrometry, ¹H NMR spectroscopy, UV/Vis/NIR absorption spectroscopy, and fluorescence spectroscopy. The optical and electrochemical measurements reveal a decrease in the HOMO–LUMO gap with increasing size of the conjugated macrocycles, and in accordance with the trend, the deactivation of the excited singlet state to the ground state is enhanced.     

Syntheses of optically active tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones and hexahydroimidazo[1,2-a]pyridin-2(3H)-ones

The reactions of (2S)-2-amino-2-substituted-N-(4-nitrophenyl)acetamides 16a-c, succindialdehyde (13), and benzotriazole afforded enantiopure (3S,5R,7aR)-5-(1H-1,2,3-benzotriazol-1-yl)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 17a-c, which were converted by sodium borohydride into (3S,7aR)-3-substituted-1-(4-nitrophenyl)tetrahydro-1H-pyrrolo[1,2-a]imidazol-2-ones 18a-c. Chiral (2S)-2-amino-2-substituted-N-(4-methylphenyl)acetamides 12a-d, easily prepared in two steps from N-Boc-alpha-amino acids 10a-d, similarly reacted with glutaraldehyde (20) and benzotriazole to generate 5-benzotriazolyl-3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 21a-d, which were converted by sodium borohydride directly into optically active 3-substituted-hexahydroimidazo[1,2-a]pyridin-2(3H)-ones 22a-d.     

Synthesis of highly branched sulfur-nitrogen heterocycles by cascade cycloadditions of [1,2]dithiolo[1,4]thiazines and [1,2]dithiolopyrroles

We report the synthesis of some new polysulfur-nitrogen heterocycles by cascade cycloadditions to readily available polycyclic 1,2-dithiole-3-thiones. Thus, treatment of bis[1,2]dithiolopyrrole dithione 1 with dimethyl acetylenedicarboxylate (DMAD) or dibenzoylacetylene (DBA) gave the 1:4 adducts 2a,b and 3a. On the other hand, cycloaddition of bis[1,2]dithiolo[1,4]thiazine dithiones 4a-d with the same dipolarophiles gave the 1:2, 1:3, or 1:4 adducts 5a-c, 6a, 7a, 8a, 9a, and 10a,c,d selectively in fair to high yields. Reaction conditions were crucial for achievement of selectivity in thermal reactions. Catalysis by scandium triflate was used in the reaction of 4a and 2 equiv of DMAD. Treatment of the [1,2]dithiolo[1,4]thiazine dithione 11 with DBA gave the 1:2, 1:3 (two isomers), and 1:4 adducts 12-14 and 15a-d selectively. Cyclic voltammetry of selected examples showed irreversible processes that were not influenced by peripheral groups bonded to the heterocyclic system.     

取代席夫碱铜金属卟啉的微波辅助合成

微波辅助合成了取代席夫碱铜金属卟啉。 实验结果表明,取代苯甲醛与四(对氨基苯基)铜金属卟啉的缩合反应速率和产率与芳香醛取代基的种类有关,含吸电子基团的芳香醛大于含给电子基团的芳香醛,且随吸电子性的增强而增加,随给电子性的增强而减少。 水杨醛席夫碱铜金属卟啉侧链可与铜离子在碱性条件下形成铜配合物,其催化氧化环己烷的转化率达到了7.68%,环己酮的选择性达到了60.87%。     

La(OTf)3-catalyzed one-pot synthesis of meso-substituted porphyrinic thiazolidinones

Abstract  

An improved synthetic procedure is developed for the regioselective nitration of a phenyl group of meso-tetraphenylporphyrin by using NaNO₂ in a mixture of trichloroacetic acid and AcOH. The meso-(4-nitrophenyl)porphyrins are successfully reduced to corresponding meso-(4-aminophenyl)porphyrins by SnCl₂ under acidic conditions. In addition, an efficient one-pot methodology for synthesizing a series of novel meso-substituted porphyrinic thiazolidinone conjugates is developed by reacting meso-(4-aminophenyl)porphyrins with various aromatic aldehydes and mercaptoacetic acid in refluxing toluene using La(OTf)₃ as a catalyst. The products obtained are characterized on the basis of their spectral data. Preliminary photophysical properties of the newly synthesized compounds are reported.     

Polyphenyl macrocyclic oligophenylenes

The Diels-Alder reaction of tribenzohexadehydro[12]annulene (12) and 3,4-diphenyl-2,5-dimethylcyclopentadienone (13) at 300 degrees C gave the triple adduct 2,3,10,11,18,19-hexaphenyl-1,4,9,12,17,20-hexamethylhexa-o-phenylene (6b) in 13% yield. NMR and X-ray analysis indicated that 6b adopts a screw conformation (C2) rather than a crown conformation (C3), and computational studies seem to rule out any interconversion of the two. Palladium-catalyzed coupling of 1,2-bis(4-bromophenyl)-3,4,5,6-tetraphenylbenzene (17) and the corresponding bis(boronic acid) 18 gave a mixture of linear and cyclic oligomers of hexaphenylbenzene containing two to six hexaphenylbenzene subunits. A macrocyclic tetramer was isolated from this mixture in 5% yield, and X-ray analysis showed it to be the "supertetraphenylene" 7 (C168H112) that contains a large central cavity and packs to form highly solvated, porous crystals. The difficulties encountered in the purification of 7 led to the development of alternative, more highly selective syntheses that give the pure macrocycle more easily but in essentially the same overall yield.     

Fluoroalkene chemistry: Part 2. Reactions of thiols with some toxic 1,2-dichlorinated polyfluorocycloalkenes

1,2-Dichlorotetrafluorocyclobutene, 1,2-dichlorohexafluorocyclopentene and 1,2-dichlorooctafluorocyclohexene were treated with an equimolar amount of benzenethiol, 2-methoxybenzenethiol, 3-methoxybenzenethiol and 4-methoxybenzenethiol in acetonitrile with potassium carbonate. Each combination of fluoroalkene and thiol gave a mixture of mono and bis vinyl substitution products whose proportions depended on the ring size of the fluorocycloalkene and the size and electronic characteristics of the thiol. Treatment of 1,2-dichlorotetrafluorocyclobutene with one or two molar equivalents of N-acetylcysteine isopropyl ester in acetonitrile with potassium carbonate produced the mono and bis vinyl substitution products accordingly. The results support the contention that the high inhalation toxicity of the fluorocycloalkenes is due to reaction with two molar equivalents of biological thiols in the lung.     

Alpha-substituted 1-aryl-3-dimethylaminopropanone hydrochlorides: potent cytotoxins towards human WiDr colon cancer cells

A series of 1-aryl-2-dimethylaminomethyl-2-propenone hydrochlorides 1 were prepared which possessed IC(50) values of less than 10 microM when examined towards human WiDr colon cancer cells. The related 1-aryl-2-dimethylaminomethyl-3-hydroxypropanone hydrochlorides 2, formed by hydration of the analogs in series 1, also had IC(50) values in the low micromolar range. On the other hand, conversion of 2-dimethylaminomethyl-1-(4-nitrophenyl)-2-propenone hydrochloride 1c into the corresponding 2-mercaptoethanol of adduct 3c led to a 37-fold reduction in potency. Two thirds of the compounds prepared in this study were more potent than a reference drug cisplatin while one third of these molecules displayed greater cytotoxicity to the WiDr cells than human CRL-2522 fibroblasts. A stability study of the 4-nitrophenyl analog in each of the series 1-3 in deuterium oxide was undertaken. In the case of 1c, replacement of the dimethylamino hydrochloride group by a hydroxy function was noted while in series 2, the loss of both water and dimethylamine hydrochloride gave rise to a mixture of two enones. The mercaptoethanol adduct 3c underwent deamination. The data obtained provide guidelines for amplifying the project in the future.     

Formation of 1,1,4,4-tetramethoxy-2,3,5,6-tetrahydroximinocyclohexane by the interaction of trinitrosophloroglucinol with hydroxylamine hydrochloride in methanol

1,1,4,4-Tetramethoxy-2,3,5,6-tetrahydroximinocyclohexane was obtained by the treatment of trinitrosoploroglucinol with hydroxylamine hydrochloride in methanol. Oxidation of the product with an alkaline solution of potassium hexacyanoferrrate(III) gave a mixture of the isomers 4,4,8,8-tetramethoxy-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]oxadiazole-1,7-dioxide.and 4,4,8,8-tetramethoxy-4H, 8H-benzo[1,2-c:4,5-c']bis-[1.2.5]oxadiazole-1,7-dioxide. Removal of the N-oxide groups from these compounds with triethyl phosphite followed by hydrolysis of the diketal groups gave 4,8-dioxo-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]-dioxazole. Reaction with malonodinitrile gave 4,8-di(dicyanomethylene)-4H, 8H-benzo[1,2-c:4,5-c']bis[1.2.5]-oxadiazole which is an analog of known electron acceptors. Novosibirsk Institute of Organic Chemistry, Siberian Branch, Russian Acaemy of Sciences, Novosibirsk 630090. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 549–553, April, 1997.     

Synthesis and antiviral activities of N-mono- and/or N,N'-di-carbamoyl and acyl derivatives of symmetrical diamines

N-carbamoyl and N-acyl diamine derivatives were synthesized from symmetrical diamines by their addition to iso(thio)cyanates, cleavage reaction of acid anhydride, or N-acylation by acyl chloride. (1R,2R)-1,2-Diaminocyclohexane [(1R,2R)-1], meso-1,2-diaminocyclohexane (meso-1), (1R,2R)-1,2-diphenylethylenediamine [(1R,2R)-3], or meso-1,2-diphenylethylenediamine (meso-3) were used as the starting symmetrical diamines. The target compounds synthesized herein were evaluated for antiviral activity with herpes simplex virus type 1 (HSV-1). A few derivatives of 1,2-diaminocyclohexane [(1R,2R)-7aa and cis-7b] with adamantyl group(s) showed significant antiviral activity (EC(50)=16.0, 27.0 microg/ml).