Tetrathiafulvalene based electroactive ligands and complexes: Synthesis,crystal structures and antifungal activity

The synthesis of two tetrathiafulvalene-appended pyridinehydrazone pyrimidine ligands, namely (Z)-4-(2-((5-([2,2′-bi(1,3-dithiolylidene)]-4-yl)pyridin-2-yl)methylene) hydrazinyl)-6-chloropyrimidine L1 and (Z)-4-(2-((6-([2,2′-bi(1,3-dithiolylidene)]-4-yl)pyridin-2-yl)methylene) hydrazinyl)-6-chloropyrimidine L2 is described. Ligand L1 was reacted with cobalt(II) to yield a cationic metal complex [Co(L1)₂] while ligand L2 was reacted with zinc(II) to afford a neutral metal complex [ZnL2Cl₂]. The crystal structure analysis of [Co(L1)₂] indicate that Co(II) ion is coordinated by six nitrogen atoms from two perpendicular ligands while in [ZnL2Cl₂], Zn(II) is coordinated by two chlorine atoms and three nitrogen atoms. The electrochemical behavior indicate that ligands L1 and L2 and the zinc(II) complex are suitable fort the preparation of crystalline radical cation salts. Finally the determination of MIC₈₀ values against C. albicans, C. glabrata, C. parapsilosis, C. krusei and E. dermatitidis revealed that the cobalt(II) metal complex [Co(L1)₂] is active against all the studied fungi.     

General methodology for the synthesis of conjugated dienic insect sex pheromones

A general methodology for the synthesis of various types of dienic insect sex pheromones (Z-E, E-Z, Z-Z) is based on the carbocupration of acetylene by functionalised or non-functionalised lithium dialkyl cuprates, followed by the coupling of the resulting Z dialkenyl cuprates with functionalised or non-functionalised E or Z alkenyl iodides under Pd° catalysis. The following compounds were efficiently synthesized with a high degree of stereoisomeric purity: (E-Z)7, 9-dodecadien,-l-yl acetate 1 (Lobesia botrana), (E-Z)10, 12-hexadecadien,-l-ol 2 (Bombyx mori), (Z-E)9, 11-tetradecadien,-l-yl acetate 3Spodoptera littoralis), (Z-E)5, 7-dodecadien-l-ol 4 (Malascoma disstria), (Z-Z)11, 13-Hexadecadien-l-al 5 (Amyelois transitella), (Z)9,ll-dodecadien-l-yl acetate 6 (Diparopsis castanea) and (Z-Z)9,11-tridecadien-l-yl acetate 22 (a known “pseudo-pheromone”).     

Photochemistry of dienones—X: Photochemistry of (e)-β-ionone oxime ethyl ether

(E)-β-ionone oximc ethyl ether [(E, E)-4] upon direct irradiation with λ either254or 313 nm yields the geometrical isomer (E, Z)-4 and (Z)-retro-γ-ionone oxime ethyl ether (Z,E)-5 as the sole primary products, illustrating (E)-(Z) isomerization (φ₃₁₃ =0.49) and a 1, 5-hydrogen shift (φ313 =0.15) respectively. From studies with triplet photosensitizers and with ethyl iodide (to enhance the singlet-triplet intersystem crossing) it is concluded that these two products in the direct irradiation result only from the singlet excited state, and that the inter-system crossing quantum yield is relatively low. Upon prolonged irradiation of (E,E)-4 with λ 313 nm the eventual products are (Z,E)-5 and (Z,Z)-5, whereas with λ 254 nm they are (E,E)-5 and [(Z,E)-5 and/or (E,Z)-5]. Upon triplet photosensitization (E,E)-4 undergoes only (E)-(Z) isomerization, leading to a mixture of all the four geometrical isomers of4. From the dependence of the geometrical isomer distribution in the photostationary state on the triplet energy of the sensitizer the triplet energies of (E,E)-4, (E, Z)-4, (Z, E)-4, and (Z, Z)-4 have been determined to be ca 55, < 55,57, and 57 $\text{kcal}\text{mol}$ respectively.     

Etude de la reaction chlorocarbene-acetals de cetenes : II. Stereoselectivite de la reaction

We have studied the stereoselectivity of the addition reaction of chloro and chloromethyl carbenoids with ketene alkylsilyl acetals. The best stereoselectivity was generally observed with the dimethyl tertiobutylsilyloxy group. With the chlorocarbenoid, using an E ketene acetal we obtained in majority (8?0%) an E α,β-ethylenic ester and using a Z ketene acetal we obtained in majority (7?0%) a Z α,β-ethylenic ester. In the case of the chloromethyl carbenoid the two ketene acetal isomers led to the same E α-substituted α,β-ethylenic ester (8?8% of selectivity). With the chlorophenylcarbenoid, formation of 9?0% of E α phenyl α,β-ethylenic ester is observed.     

Silylation as a protective method in acetylene chemistry. : Syntheses in the polyeneyne series,R3Si(CC)n(CHCH)4(CC)nSiR3 and H(CC)n(CHCH)4(CC)nH (n = 1, 2)

The Grignard reagents R₃Si(CC)_nMgBr (R = Me, n = 1; R = Et, n = 1,2) couple with cyclooctatetraene dibromide 1 in THF to give, as major products, the silyl-stabilised E, Z, Z, E-polyeneynes, Me₃SiCC(CHCH)₄CCSiMe₃3a, Et₃SiCC(CHCH)₄CCSiEt₃4a and Et₃Si(CC)₂(CHCH)₄(CC)₂SiEt₃6a together with minor proportions of configurational isomers Z, E, Z, Z 3c, all -E 3b, 4b, 6b and compounds in which a bicyclo-octadiene structure 2, 5 and 7 is retained. Irradiation converts the cis(Z)-rich isomers e.g. 3c into the all-trans(E) products. Treatment of the bissilyl compounds 3, 4 and 6 with aqueous base liberates the respective parent polyeneynes, H(CC)_n(CHCH)₄(CC)_nH, in each case.     

Synthesis of steroid 24,20-lactones by means of phenylselenolactonization

A synthesis of (20 R)- and (20 S)-3β-methoxy-5-cholen-24,20-lactones (7a and 7b) from 3β-methoxy-5-androsten-17-one (2) is described. The 17-ketone 2 was treated with isopropenyllithium to give 3β-methoxy-17α-(prop-l'-en-2'-ylo)-5-androsten-17β-ol (3). Compound 3 on reaction with ethyl orthoacetate and Claisen rearrangement of intermediate 17β-orthoester furnished ethyl esters of (E)- and (Z)-3β-methoxy-chol-5,17(20)-diene-24-acids (4b and 4a). Hydrolysis of ester groups in 4a and 4b and phenylselenolactonization afforded stereospecifically and regioselectively unsaturated (20 R)- and (20 S)-3β-methoxy-chol-5,16-diene-24, 20-lactones(6a and 6b), respectively. Reduction of double bond 16-17 in 6a and 6b gave the final products 7a and 7b. The phenylselenolactonization of(E)- and (Z)-3β-methoxy-chol-5,17(20)-diene-24-acids (5b and 5a) and spontaneous elimination of phenylselenyl moiety was investigated and compared with iodolactonization of the same unsaturated acids.     

Simple syntheses of isomers of muconaldehyde and 2-methylmuconaldehyde

Periodate oxidation of cis-1,2-dihydrocatechol (3a) affords (Z,Z)-muconaldehyde (2b), which can be readily converted (thermolysis and triethylamine catalysis, respectively) into its (E,Z)- (2c) and (E,E)-isomer (2a). Similarly, cis-1,2-dihydro-3-methylcatechol (3b) gives(Z,Z)-2-methylmuconaldehyde (2d) and thence (E,E)-2-methylmuconaldehyde (2c).     

Insect pheromones : Synthesis of chiral sex pheromone components of several species of trogoderma (coleoptera: dermestidae)

The (S)-enantiomers of (Z)- and (E)-14-methyl-8-hexadecen-1-ol, 1 and 4, respectively, and of (Z)- and (E)-14-methyl-8-hexadecenal, 6 and 7, respectively, which are sex pheromone components of dermestid beetles, have been synthesized in high optical purity starting from optically pure (S)-2-methyl-1-butanol. The preparation of 1 has been carried out using a new general method for reducing stereoselectively and in high yield ω-alkynols to the corresponding (E)-alkenols. The rotatory power of optically pure 1, 4, 6 and 7 has been established.     

Hochdruckversuche—VIII: Die thermische isomerisierung von 1,2-diphenyl-cyclobuten-(1)-cis-3,4-dicarbonsäure-dimethyl-ester zu 3,4-diphenylmuconsäure-estern

The ring opening reaction of dimethyl-1,2-diphenyl-cyclobutene-cis-3,4-dicarboxylate (1) into (E,Z) dimethyl-3,4-diphenylmuconate (2) is accelerated 1.4 times by a pressure of 9500 atm. In addition the (Z,Z) dimethyl-3,4-diphenyl-muconate (3), forbidden by the Woodward-Hoffmann-rules, is generated. By determination of the rate constants we could show that 3 is not formed by the ring opening of 1 but by an isomerization of 2. This reaction is accelerated 11 times by a pressure of 9500 atm.     

Formation of enamine Schiff bases by ring cleavage of pyridine

On treatment with diphenyldichloromethane or anisal chloride in the presence of acetone and aqueous sodium hydroxide, pyridine undergoes condensation and ring cleavage to yield the enamine Schiff bases 1,1-diphenyl-2-azadeca-1,3Z,5Z,7E-tetraen-9-one (1) and 1-(4-methoxyphenyl)-2-azadeca-1E,3Z,5Z,7E-tetraen-9-one (7). The reaction proceeds through attack of acetonyl carbanion on the initially formed bis-pyridinium salt, followed by ring scission with elimination of one equivalent of pyridine. The structure and stereochemistry of the 2-azatetraene (1) was confirmed by X-ray crystallography.     

Hochdruckversuche—IX: Die thermische isomerisierung von 1,2-diphenyl-3-methyl-cyclobuten-(1)-cis-3,4-dicarbonsäuredimethylester und 3,4-dimethyl-1,2-diphenyl-cyclobuten-(1)-cis-3,4-dicarbonsäuredimethylester

Dimethyl-1,2-diphenyl-3-methyl-cyclobutene-(1)-cis-3,4-dicarboxylate 2 leads in a thermal reaction to an equilibrium with (E, Z)-dimethyl-3,4-diphenyl-5-methyl-muconate (4). The equilibrium is shifted to the cyclic compound by pressure. Dimethyl-3,4-diphenyl-cyclobutene-(1,2-diphenyl-cyclobutene-(1)-cis-3,4-dicarboxylate (3) isomerizes thermally to (E, Z)-dimethyl-2,5-dimethyl-3,4-diphenylmuconate (6). Both reactions are accelerated by pressure. The activation volumes ΔV₀⁺ are given for each ringopening reaction.     

Synthesis of arotinoid acid and temarotene using mixed (Z)-1,2-bis(organylchalcogene)-1-alkene as precursor

An efficient and novel total synthesis of the two bioactive retinoids temarotene and arotinoid acid (TTNPB) is described. The key steps in this process include the regio and stereoselective hydrotelluration of thioacetylene 9 and Te/Li transmetalation of mixed (Z)-1,2-bis(organylchalcogene)-1-alkene (Z)-3. The subsequent reaction involving the β-phenylthio vinyl lithiated intermediate 10 with dimethyl sulfate gave the (E)-vinyl sulfide 11. The Ni⁺² cross-coupling of 11 with the corresponding phenylzinc bromide and p-oxazoline phenylzinc bromide 12 afforded the respective temarotene 2 and retinoid-oxazoline substituted 13. Finally, compound 13 was deprotected with HCl to furnish arotinoid acid (TTNPB) 1.     

Dialkyl formyl-1 methylphosphonates α-fonctionnels—II : Preparation par voie thermique et transformation en heterocycles α-phosphoniques

The thermal condensation of functional phosphonates bearing strongly withdrawing groups (RO)₂P(O)CH₂Z1 with dimethylformamide dimethyl acetal gives corresponding β-functional, β-phosphonic enamines (RO)₂P(O)C(Z)=CHNMe₂2. Acid or basic hydrolysis of the enamines frequently gives the free aldehyde (RO)₂P(O)CH(Z)—CHO 3. We show that the enamines can be used with success for the synthesis of heterocycles like, pyrazoles 4, pyrimidines 5, benzodiazepine 6 or indole 7, all of them substituted with a phosphonate group.     

Total synthesis of citreomontanin and its C18Z polyene isomer

A total synthesis of citreomontanin 5, a biologically active mycotoxin isolated from P. pedemontanum, and its C₁₈Z isomer 6, is described     

Photochemical formation of chrysanthemic acid and cyclopropylacrylic acid derivatives: A case of multiplicity-dependent regiospecificity in the di-π-methane rearrangement

Photochemical transformations of methyl E- and Z - 4,4,6 - trimethyl - 2,5 - dienoate (5a) and of the corresponding acids (5b) have been investigated. In contrast to similar pure hydrocarbon di-π-methanes, these aliphatic α,β-unsaturated car?ylic acid derivatives react from both the singlet and the triplet excited states and form different types of vinylcyclopropanes depending on multiplicity. When irradiated in acetone, both 5aE and 5aZ give methyl E - 3(2,2,3,3 - tetramethylcyclopropyl)prop - 2 - enoate (8aE). The same is observed for the corresponding acids. Direct irradiation of 5aE, but not of 5aZ, readily gives methyl E-chrysanthemate (4aE). Only singlet excited 5Z reacts by internal hydrogen abstraction to cyclopropylacetic add derivatives (7). Procedures for independent synthesis of 7 and 8 are described.     

A facile and highly stereoselective synthesis of (2E)-, (2E,4E)-unsaturated amides and related natural products

A facile synthesis of (2E)-, (2E, 4E)-unsaturated amides was achieved via arsonium bromides with high stereoselectivity. Its application to the synthesis of related natural products 4 and 5 is also reported.     

Stereo- and enantioselective synthesis of some e,z dienols and ethers.

Functionnalized E,Z dienes (?) 2 have been prepared in a highly stereo- and enantioselective manner using chiral pentadienyl iron tricarbonyl complexes 1.     

Triene electrocyclizations: Some structure reactivity relations

Two stereoselective routes for the synthesis of trienes having a central cis double bond have been devised. These were employed for the synthesis of (Z)-1-(cyclohexen-1-yl)-1,3-butadiene (1), (Z,E)-1-(cyclohexen-1-yl)-1,3-pentadiene (2), (Z,Z)-1-(cyclohexen-1-yl)-1,3-pentadiene (3), 1,2-divinyleyclohexene (4), (E,Z)-1-phenyl-1,3,5-hexatriene (5), (Z,Z)-1-phenyl-1,3,5-hexatriene (6) and (E,Z)-1-(p-chlorophenyl)-1,3,5-hexatriene (7). Rates of the thermal electrocyclization and activation parameters were measured for these in inert solvents. The results are tabulated below.

     

19.

Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2 (Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2 (Z = Me2Si, H2C; E = S, Se)     

Uwe Herzog  Uwe Böhme 《Silicon Chemistry》2003,2(1-2):77-92

Reactions of ClMe₂Si–Z–SiMe₂Cl (Z = SiMe₂ (1a), CH₂ (1c), O (1e)) with Li₂E (E = S, Se) yielded eight-membered ring compounds (SiMe₂ZSiMe₂E)₂ (3a–d) as well as acyclic oligomers (SiMe₂ZSiMe₂E)_x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R₂MCl₂) are reacted with Li₂E (E = S, Se, Te), six-membered ring compounds Z(SiMe₂E)₂MR₂ (4a–7g) are formed exclusively. Five-membered rings Z₂(SiMe₂)₂E (Z = SiMe₂ (8a–c), CH₂ (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe₂Si–(SiMe₂)₂–SiMe₂Cl (1b) or the disilylethane ClMe₂Si–(CH₂)₂–SiMe₂Cl (1d) by treatment with Li₂E. All products were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹¹⁹Sn, ⁷⁷Se, ¹²⁵Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.     

20.

A model for triterpene side-chain synthesis. 2     

《Tetrahedron》1988,44(4):1007-1014

A bicyclic model for 17-keto derivatives of triterpenes, trans -1,6-dimethyl-2-methoxybicyclo[4.3.0] nonan-7-one (1), was used to explore side-chain construction concurrent with oxidation at C-8 (triterpene C-16). Oxidation of methylene derivative 2 with selenium dioxide gave β alcohol 14, and borohydride reduction of the corresponding ketone (15) led to the α epimer 16. Each allylic alcohol (14 and 16) reacted stereospecifically with phenylsulfenyl chloride to give, respectively, diastereoisomeric sulfoxides 20 and 19. The latter yielded a conjugate base that was methylated selectively to give sulfoxide 21. Desulfuration of 21 with trimethylphosphite generated the ethylidene α alcohol 22, and following PDC oxidation, E enone 25.This enone was a minor product from an alternative synthesis beginning with ethylidene derivative 3. Treatment of 3 with selenium dioxide followed by PDC gave the isomeric Z enone 24 as the major product. Reaction of 24 with lithium bis-4-methyl-3-pentenylcuprate proceeded by a facial-selective conjugate addition to the euphane CD model 26. The E isomer 25, under similar conditions, gave only an unresolved mixture. These results are compared with similar steroid reactions reported by Trost and Schmuff¹¹.     

Compound	k1 x 105	(sec?1)	Temp (°C)	ΔH3	ΔS3
1	12·8	132	29	?6
2	12·5	132	29	?1
3	2·6	173	34	?5
4	3·86	125	25	?15
5	16·0	145	28	?8
6	3·0	195
7	15·0	145	25	?18(?)

Five-, six- and eight-membered ring organosilicon chalcogenides of the types Z2(SiMe2)2E (Z = Me2Si, H2C; E = S, Se, Te), Z(SiMe2E)2MR2 (Z = Me2Si, H2C, O; E = S, Se, Te; M = Si, Ge, Sn, R = Me, Ph) and (SiMe2ZSiMe2E)2 (Z = Me2Si, H2C; E = S, Se)

Reactions of ClMe₂Si–Z–SiMe₂Cl (Z = SiMe₂ (1a), CH₂ (1c), O (1e)) with Li₂E (E = S, Se) yielded eight-membered ring compounds (SiMe₂ZSiMe₂E)₂ (3a–d) as well as acyclic oligomers (SiMe₂ZSiMe₂E)_x of different chain lengths. If 1:1 molar mixtures of 1a, 1c or 1e and a diorganodichlorosilane, -germane or -stannane (R₂MCl₂) are reacted with Li₂E (E = S, Se, Te), six-membered ring compounds Z(SiMe₂E)₂MR₂ (4a–7g) are formed exclusively. Five-membered rings Z₂(SiMe₂)₂E (Z = SiMe₂ (8a–c), CH₂ (9a–c); E = S, Se, Te) are obtained starting from the tetrasilane ClMe₂Si–(SiMe₂)₂–SiMe₂Cl (1b) or the disilylethane ClMe₂Si–(CH₂)₂–SiMe₂Cl (1d) by treatment with Li₂E. All products were characterized by multinuclear NMR spectroscopy (¹H, ¹³C, ²⁹Si, ¹¹⁹Sn, ⁷⁷Se, ¹²⁵Te, including coupling constants) and the effects of the different ring sizes towards NMR chemical shifts are discussed.     

A model for triterpene side-chain synthesis. 2

A bicyclic model for 17-keto derivatives of triterpenes, trans -1,6-dimethyl-2-methoxybicyclo[4.3.0] nonan-7-one (1), was used to explore side-chain construction concurrent with oxidation at C-8 (triterpene C-16). Oxidation of methylene derivative 2 with selenium dioxide gave β alcohol 14, and borohydride reduction of the corresponding ketone (15) led to the α epimer 16. Each allylic alcohol (14 and 16) reacted stereospecifically with phenylsulfenyl chloride to give, respectively, diastereoisomeric sulfoxides 20 and 19. The latter yielded a conjugate base that was methylated selectively to give sulfoxide 21. Desulfuration of 21 with trimethylphosphite generated the ethylidene α alcohol 22, and following PDC oxidation, E enone 25.This enone was a minor product from an alternative synthesis beginning with ethylidene derivative 3. Treatment of 3 with selenium dioxide followed by PDC gave the isomeric Z enone 24 as the major product. Reaction of 24 with lithium bis-4-methyl-3-pentenylcuprate proceeded by a facial-selective conjugate addition to the euphane CD model 26. The E isomer 25, under similar conditions, gave only an unresolved mixture. These results are compared with similar steroid reactions reported by Trost and Schmuff¹¹.