Annulenoide Tetrathiafulvalene:, 5,16‐Bis(1,3‐benzodithiol‐2‐yliden)‐5,16‐dihydrotetraepoxy‐ und 5,16‐Bis(1,3‐benzodithiol‐2‐yliden)‐5,16‐dihydrotetraepithio[22]annulene(2.1.2.1)

Annulenoid Tetrathiafulvalenes: 5,16‐Bis(1,3‐benzodithiol‐2‐ylidene)‐5,16‐dihydrotetraepoxy‐ and 5,16‐Bis(1,3‐benzodithiol‐2‐ylidene)‐5,16‐dihydrotetraepithio[22]annulenes(2.1.2.1) The title compounds are among the first tetrathiafulvalenes with annulene spacers, here with tetraepoxy‐[22]annulene(2.1.2.1) (see 3a ), tetraepithio[22]annulene(2.1.2.1) (see 3b ), and diepithiodiepoxy[22]annulene(2.1.2.1) (see 23 ) units. The annulenoid tetrathiafulvalenes 3a and 3b are prepared by cyclizing McMurry coupling of the 5,5′‐(1,3‐benzodithiol‐2‐ylidenemethylene)bis[furan‐ or thiophene‐2‐carbaldehydes] ( 8a or 8b , resp.) or by Wittig reaction of (1,3‐benzodithiol‐2‐yl)tributylphosphonium tetrafluoroborate ( 13b ) with tetraepoxy[22]annulene(2.1.2.1)‐1,12‐dione 20 (formation of 3a ) or diepithiodiepoxy[22]annulene(2.1.2.1)‐1,12‐dione 22 (formation of 23 ). The annulenoide tetrathiafulvalene 3a is obtained as a mixture of the isomers (E,E)‐ and (Z,Z)‐ 3a . At 130°, (Z,Z)‐ 3a rearranges quantitatively into the (E,E)‐isomer. Isomer (E,E)‐ 3a is a dynamic molecule, where the (E)‐ethene‐1,2‐diyl bridges rotate around the adjacent σ‐bonds. The tetraepithioannulene derivative 3b as well as 23 only exist in the (Z,Z)‐configuration. The oxidation of (E,E/Z,Z)‐ 3a with Br₂ yields the annulene‐bridged tetrathiafulvalene dication (E,E)‐ 3a _Ox, while with 4,5‐dichloro‐3,6‐dioxocyclohexa‐1,4‐diene‐1,2‐dicarbonitrile (DDQ) obviously only the radical cation 3a _Sem is formed, which belongs to the class of cyanine‐like violenes. The annulenoide tetrathiafulvalenes 3b and 23 , which exist only in the (Z,Z)‐configuration, obviously for steric reasons, cannot be oxidized by DDQ. Electrochemical studies are in agreement with these results.     

A novel stereoselective synthesis of (2Z)‐2‐arylsulfanylallylic alcohols by tin–lithium exchange of (E)‐α‐stannylvinyl sulfides

Tin–lithium exchange reaction of (E)‐α‐stannylvinyl sulfides 1 with n‐butyllithium gave (Z)‐α‐arylsulfanylvinyllithiums 2 , which reacted with aldehydes or ketones 3 to afford stereoselectively (2Z)‐2‐arylsulfanylallylic alcohols 4 in good to high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:639–643, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/hc.20487     

A highly efficient synthesis of (Z)‐1‐aryl‐2‐silyl‐1‐ stannylethenes and their conversion to (E)‐2‐ arylethenyl‐, (Z)‐2‐(2‐pyridyl)ethenyl‐ and allenyl‐silanes

A Pd(dba)₂–P(OEt)₃ combination allowed the silastannation of arylacetylenes, 1‐hexyne or propargyl alcohols with tributyl(trimethylsilyl)stannane to take place at room temperature, producing (Z)‐2‐silyl‐1‐stannyl‐1‐substituted ethenes in high yields. Novel silyl(stannyl)ethenes were fully characterized by ¹H‐, ¹³C‐, ²⁹Si‐ and ¹¹⁹Sn‐NMR as well as infrared and mass analyses. Treatment of a series of (Z)‐1‐aryl‐2‐silyl‐1‐stannylethenes and (Z)‐1‐(3‐pyridyl)‐2‐silyl‐1‐stannylethene with hydrochloric acid or hydroiodic acid in the presence of tetraethylammonium chloride (TEACl) or tetrabutylammonium iodide (TBAI) led to the exclusive formation of (E)‐trimethyl(2‐arylethenyl)silanes with high stereoselectivity. A similar reaction of (Z)‐1‐(2‐anisyl)‐2‐silyl‐1‐stannylethene also produced E‐type trimethyl[2‐(2‐anisyl)ethenyl]silane, while (Z)‐trimethyl [2‐(2‐pyridyl)ethenyl]silane was produced exclusively from (Z)‐1‐(2‐pyridyl)‐2‐silyl‐1‐stannylethene. Protodestannylation of (Z)‐1‐[hydroxy(phenyl)methyl]‐2‐silyl‐1‐stannylethene with trifluoroacetic acid took place via the β‐elimination of hydroxystannane, providing trimethyl(3‐phenylpropa‐1,2‐dienyl)silane quite easily. The destannylation products were also fully characterized. Copyright © 2007 John Wiley & Sons, Ltd.     

(E/Z)‐Isomerization of (all‐E)‐5,6‐Diepikarpoxanthin

(all‐E)‐5,6‐Diepikarpoxanthin (=(all‐E,3S,5S,6S,3′R)‐5,6‐dihydro‐β,β‐carotene‐3,5,6,3′‐tetrol; 1 ) was submitted to thermal isomerization and I₂‐catalyzed photoisomerization. The structures of the main products, i.e. (9Z)‐ ( 2 ), (9′Z)‐ ( 3 ), (13Z)‐ ( 4 ), (13′Z)‐ ( 5 ), and (15Z)‐5,6‐diepikarpoxanthin ( 6 ), were determined by their UV/VIS, CD, ¹H‐NMR, and mass spectra. In addition, (9Z,13′Z)‐ or (13Z,9′Z)‐ ( 7 ), (9Z,9′Z)‐ ( 8 ), and (9Z,13Z)‐ or (9′Z,13′Z)‐5,6‐diepikarpoxanthin ( 9 ) were tentatively identified as minor products of the I₂‐catalyzed photoisomerization.     

A New Monomer for π‐Conjugated Polymers — Synthesis and Characterization of Bis((Z)‐5‐phenyl‐2‐phenylmethylidene‐1, 3‐dithiole‐4‐yl)monosulfane

Bis((Z)‐5‐phenyl‐2‐phenylmethylidene‐1, 3‐dithiole‐4‐yl)monosulfane ( 6 ), a molecule consisting of two diphenyldithiafulvene units connected by a sulfur bridge, was synthesized by the selective lithiation of (Z)‐4‐phenyl‐2‐phenylmethylidene‐1, 3‐dithiole ( 7a ) at the endocyclic double bond and by subsequent reaction of the lithiated intermediate with bis(phenylsulfonyl)sulfane. Since this reaction sequence proceeded with retention of configuration, of three possible isomers (E, E, Z, E, and Z, Z) only the Z, Z form was obtained. On the basis of the X‐ray structure analysis and the NMR‐spectroscopic characterization of 6 supplemented by the NMR parameters of (E)‐ and (Z)‐4‐phenyl‐2‐phenylmethylidene‐1, 3‐dithiole, it was demonstrated that two characteristic ⁵J coupling constants of the proton at the exocyclic double bond indicate the configuration (Z or E) of disubstituted dithiafuvene derivatives.     

Quinolone Analogs 13: Synthesis of Novel 1,1′‐(2‐Methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) and Related Compounds

The reaction of the 4‐hydroxyquinoline‐3‐carboxylate 6 with pentaerythritol tribromide gave the 1,1′‐(2‐methylenepropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 11 , whose reaction with bromine afforded the 1,1′‐(2‐bromo‐2‐bromomethylpropane‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 12 . Compound 12 was transformed into the (Z)‐1,1′‐(2‐acetoxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylate) 13 or (E)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylate) 14 . Hydrolysis of the dimer (Z)‐ 13 or (E)‐ 14 with potassium hydroxide provided the (E)‐1,1′‐(2‐hydroxymethylpropene‐1,3‐diyl)di(4‐quinolone‐3‐carboxylic acid) 15 or (Z)‐1,1′‐[2‐(imidazol‐1‐ylmethyl)propene‐1,3‐diyl]di(4‐quinolone‐3‐carboxylic acid) 16 , respectively. The nuclear Overhauser effect (NOE) spectral data supported that those hydrolysis resulted in the geometrical conversion of (Z)‐ 13 into (E)‐ 15 or (E)‐ 14 into (Z)‐ 16 .     

Two‐ and Three‐Component Reactions Leading to New Enamines Derived from 2,3‐Dicyanobut‐2‐enoates

The three‐component reactions of 1‐azabicyclo[1.1.0]butanes 1 , dicyanofumarates (E)‐ 5 , and MeOH or morpholine yielded azetidine enamines 8 and 9 with the cis‐orientation of the ester groups at the C?C bond ((E)‐configuration; Schemes 3 and 4). The structures of 8a and 9d were confirmed by X‐ray crystallography. The formation of the products is explained via the nucleophilic addition of 1 onto (E)‐ 5 , leading to a zwitterion of type 7 (Scheme 2), which is subsequently trapped by MeOH or morpholine ( 10a ), followed by elimination of HCN. Similarly, two‐component reactions between secondary amines 10a – 10c and (E)‐ 5 gave products 12 with an (E)‐enamine structure and (Z)‐oriented ester groups. On the other hand, two‐component reactions involving primary amines 10d – 10f or NH₃ led to the formation of the corresponding (Z)‐enamines, in which the (E)‐orientation of ester groups was established.     

Cycloaddition Reactions of 7‐Benzylidenecycloocta‐1,3,5‐triene with Ethenetetracarbonitrile and 4‐Phenyl‐3H‐1,2,4‐triazole‐3,5(4H)‐dione

An (E)/(Z) mixture (3 : 2) of 7‐benzylidenecycloocta‐1,3,5‐triene ( 5 ) is obtained when 1‐benzylcycloocta‐1,3,5,7‐tetraene ( 7 ), prepared by an improved procedure, is treated with t‐BuOK in THF. Alternatively, a ca. 9 : 1 mixture (E)/(Z)‐ 5 can be prepared in a Wittig reaction involving benzaldehyde and cycloocta‐2,4,6‐trien‐1‐ylidenetriphenylphoshorane ( 9 ). Treatment of (E)/(Z)‐ 5 88 : 12 with ethenetetracarbonitrile (TCNE) gave a complex mixture of products, from which seven mono‐adducts and two bis‐adducts were isolated (Sect. 2.2.1). Of the mono‐adducts, four are π4+π2 adducts: two ((E)‐ and (Z)‐isomers) are derived from valence tautomers of the two isomers of (E)/(Z)‐ 5 , while it is tentatively suggested that the other two (again (E)‐ and (Z)‐isomers) are formed from the intermediacy of a pentadienyl zwitterion (Sect. 2.3). The remaining three mono‐adducts, two of which are epimers, are π8+π2 adducts. It is suggested that they are derived from the intermediacy of homotropylium zwitterions (Sect. 2.3). For the two bis‐adducts, it is postulated that they are derived from an initial π2+π2 cycloaddition involving the homotropylium zwitterions followed by π4+π2 cycloaddition to the valence tautomer of each of the π2+π2 cycloadducts. With 4‐phenyl‐3H‐1,2,4‐triazole‐3,5(4H)‐dione ( 6 ), (E)/(Z)‐ 5 91 : 9 yielded two π4+π2 cycloadducts ((E)‐ and (Z)‐isomers) as well as two epimeric π8+π2 cycloadducts (Sect. 2.2.2). The intermediacy of pentadienyl (tentative suggestion) and homotropylium zwitterions accounts for the formation of the products (Sect. 2.3).     

1,2‐Bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile: Enol Ethers and Ketene Acetals as Cycloaddition Partners

(E)‐ and (Z)‐1,2‐bis(trifluoromethyl)ethene‐1,2‐dicarbonitrile ((E)‐ and (Z)‐BTE, resp., =(E)‐ and (Z)‐2,3‐bis(trifluoromethyl)but‐2‐enedinitrile) were used as a stereochemical probe in studying (2+2) cycloadditions of acceptor with donor alkenes. The additions to methyl (E)‐ and (Z)‐propenyl ether gave rise to the eight conceivable cyclobutanes 8 , although in different ratios in reactions of (E)‐ and (Z)‐BTE. The ¹⁹F‐NMR data served the structural assignment and the quantitative analysis. The mechanistic discussion is based on rotations and ring closures of the assumed 1,4‐zwitterionic intermediates. Dimethylketene dimethyl acetal, methylketene dimethyl acetal, and ketene diethyl acetal show an increasing rate in their reactions with BTE as well as in the equilibration of the cycloadducts.     

Superheteroaromaten mit Furan‐Bausteinen: Isomere antiaromatische Tetraepoxy[36]annulene(6.4.6.4) und aromatische Tetraoxa[34]porphyrin(6.4.6.4)‐Dikationen

Superheteroaromatic Systems with Furan Building Blocks: Isomeric Antiaromatic Tetraepoxy[36]annulenes(6.4.6.4) and Aromatic Tetraoxa[34]porphyrin(6.4.6.4) Dications The title compounds are available by a twofold cyclizing Wittig reaction of (all‐E)‐3,3′‐(hexa‐1,3,5‐triene‐1,6‐diyldifuran‐5,2‐diyl)bis[prop‐2‐enal] ( 4 ) with (all‐E)‐(hexa‐1,3,5‐triene‐1,6‐diyl)bis(furan‐5,2‐diylmethylene)bis[triphenylphosphonium] dibromide ( 7 ). Two conformational isomers 2a / 2a ′ of (Z,E,E,E,E,Z,E,E,E,E)‐tetraepoxy[36]annulene(6.4.6.4) are obtained. The oxidation of 2a / 2a ′ yields two (E,E,Z,E,E,E,E,Z,E,E)‐tetraoxa[34]porphyrin(6.4.6.4) dications 3a / 3a ′, which are conformers, too. The oxidation of 2a / 2a ′ is accompanied by the isomerization of four ethen‐1,2‐diyl bridges. The reduction of the dications 3a / 3a ′ leads to the new (E,E,Z,E,E,E,E,Z,E,E)‐tetraepoxy[36]annulene(6.4.6.4) ( 2b ) and (E,E,E,Z,E,E,E,E,Z,E)‐tetraepoxy[36]annulene(6.4.6.4) ( 2c ). In 2b as well as in 2c , both 1,3‐butadiene‐1,4‐diyl bridges are rotating until −90°. The Δδ values, i.e., the maximum δ difference of the `inner' and `outer' perimeter protons of 3a / 3a ′ (26.62 and 25.32 ppm) are of the same size as the Δδ value of the tetramethyl[34]porphyrin(5.5.5.5) dication ( 1 ; Δδ=25.3 ppm); therefore, they might be called `superheteroaromatic' too. The Δδ values of the tetraepoxy[36]annulenes(6.4.6.4) ( 2a – c ; Δδ=2.3 – 3.3 ppm) establish that they are still paratropic; they represent the most expanded antiaromatic systems yet known.     

Stereoselective Synthesis of (Z)‐4‐(2‐Bromovinyl)benzene‐sulfonyl Azide and Its Synthetic Utility for the Transformation to (Z)‐N‐[4‐(2‐Bromovinyl)benzenesulfonyl]imidates

A novel method for the stereoselective synthesis of (Z)‐4‐(2‐bromovinyl)benzenesulfonyl azide by simultaneous azidation and debrominative decarboxylation of anti‐2,3‐dibromo‐3‐(4‐chlorosulfonylphenyl)propanoic acid using NaN₃ only was developed. Facile transformation of (Z)‐4‐(2‐bromovinyl)benzenesulfonyl azide to (Z)‐N‐[4‐ (2‐bromovinyl)benzenesulfonyl]imidates was also achieved by Cu‐catalyzed three‐component coulping of (Z)‐4‐(2‐bromovinyl)benzenesulfonyl azide, terminal alkynes and alcohols/phenols.     

Four (E,Z,E)‐1‐(4‐alkoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐trienes

The crystal structures of the four E,Z,E isomers of 1‐(4‐alk­oxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, namely (E,Z,E)‐1‐(4‐methoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₁₉H₁₇NO₃, (E,Z,E)‐1‐(4‐ethoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₀H₁₉NO₃, (E,Z,E)‐1‐(4‐nitro­phen­yl)‐6‐(4‐n‐propoxyphen­yl)hexa‐1,3,5‐triene, C₂₁H₂₁NO₃, and (E,Z,E)‐1‐(4‐n‐butoxy­phen­yl)‐6‐(4‐nitro­phen­yl)hexa‐1,3,5‐triene, C₂₂H₂₃NO₃, have been determined. Inter­molecular N⋯O dipole inter­actions between the nitro groups are observed for the meth­oxy derivative, while for the eth­oxy derivative, two adjacent mol­ecules are linked at both ends through N⋯O dipole–dipole inter­actions between the N atom of the nitro group and the O atom of the eth­oxy group to form a supra­molecular ring‐like structure. In the crystal structures of the n‐prop­oxy and n‐but­oxy derivatives, the shortest inter­molecular distances are those between the two O atoms of the alk­oxy groups. Thus, the nearest two mol­ecules form an S‐shaped supra­molecular dimer in these crystal structures.     

(E/Z)‐Isomerization of 3′‐Epilutein

3′‐Epilutein (=(all‐E,3R,3′S,6′R)‐4′,5′‐didehydro‐5′,6′‐dihydro‐β,β‐carotene‐3,3′‐diol; 1 ), isolated from the flowers of Caltha palustris, was submitted to both thermal isomerization and I₂‐catalyzed photoisomerization. The structures of the main products (9Z)‐ 1 , (9′Z)‐ 1 , (13Z)‐ 1 , (13′Z)‐ 1 , (15Z)‐ 1 , and (9Z,9′Z)‐ 1 were determined based on UV/VIS, CD, ¹H‐NMR, and MS data.     

(E)‐,(Z)‐Parallel Preparative Methods for Stereodefined β,β‐Diaryl‐ and α,β‐Diaryl‐α,β‐unsaturated Esters: Application to the Stereocomplementary Concise Synthesis of Zimelidine

Parallel and practical methods for the preparation of both (E)‐ and (Z)‐β‐aryl¹‐β‐aryl²‐α,β‐unsaturated esters 1 and (E)‐ and (Z)‐α‐aryl¹‐β‐aryl²‐α,β‐unsaturated esters 2 are described. These methods involve accessible, robust, stereocomplementary N‐methylimidazole (NMI)‐mediated enol tosylations (14 examples, 70–99 % yield), as well as stereoretentive Suzuki–Miyaura cross‐couplings (36 examples, 64–99 % yield). The highlighted feature of the present protocol is the use of parallel and stereocomplementary approaches to obtain highly (E)‐ and (Z)‐pure products 1 and 2 by utilizing sequential enol tosylations and cross‐coupling reactions. An expeditious and parallel synthesis of (E)‐ and (Z)‐zimelidine ( 3 ), which is a highly representative selective serotonin reuptake inhibitor (SSRI), was performed by utilizing the present methods.     

Diepoxy[18]annulene(10.0) : (Z,E,Z,E,Z)‐Diepoxy[18]annulen(10.0) – ein hochdynamisches Annulen

Diepoxy[18]annulenes(10.0): ( Z , E , Z , E , Z )‐Diepoxy[18]annulene(10.0) – a Highly Dynamic Annulene The McMurry reaction of (all‐E)‐5,5′‐([2,2′‐bifuran]‐5,5′‐diyl)bis[penta‐2,4‐dienal] ( 13 ) only occurs intramolecularly to give a mixture of the diepoxy[18]annulenes(10.0) 6 and 7 . Tetraepoxy[36]annulene(10.0.10.0) resulting from an intermolecular McMurry reaction is not formed. According to spectroscopic data, 6 is (Z,E,Z,E,Z)‐ and 7 (Z,E,E,Z,E)‐configured. The ¹H‐NMR data confirm that in 6 the (E)‐ethene‐1,2‐diyl bonds (C(11)=C(12) and C(15)=C(16)) rotate around the adjacent σ‐bonds. Beginning at −70°, this rotation freezes, and 6 is becoming a diatropic aromatic ring system. Beside [18]annulene itself, (Z,E,Z,E,Z)‐diepoxy[18]annulene(10.0) 6 is the only hitherto known [18]annulene derivative with dynamic properties.     

Synthesis of Citronellal by RhI‐Catalysed Asymmetric Isomerization of N,N‐Diethyl‐Substituted Geranyl‐ and Nerylamines or Geraniol and Nerol in the Presence of Chiral Diphosphino Ligands,under Homogeneous and Supported Conditions

For the asymmetric isomerization of geranyl‐ or neryldiethylamine ((E)‐ or (Z)‐ 1 , resp.) and allyl alcohols geraniol or nerol ((E)‐ or (Z)‐ 2 , resp.) to citronellal ( 4 ) in the presence of a [Rh^I(ligand)cycloocta‐1,5‐diene)]⁺ catalyst, the atropic ligands 5 – 11 are compared under homogeneous and polymer‐supported conditions with the non‐C₂‐symmetrical diphosphino ferrocene ligands 12 – 16 . The ^tBu‐josiphos ligand 13 or daniphos ligand 19 , available in both antipodal series, already catalyse the reaction of (E)‐ 1 at 20° (97% e.e.) and favourably compare with the binap ligand 5 (see Table 1). Silica‐gel‐ or polymer‐supported diphosphino ligands usually afford similar selectivity as compared to the corresponding ligands applied under homogeneous conditions, but are generally less reactive. In this context, a polymer‐supported ligand of interest is the polymer‐anchored binap (R)‐ 6 , in terms of reactivity, selectivity, and recoverability, with a turnover of more than 14400.     

Z/E‐Isomerism of 3‐[4‐(dimethylamino)phenyl]‐2‐(2,4,6‐tribromophenyl)acrylonitrile: crystal structures and secondary intermolecular interactions

The Z and E isomers of 3‐[4‐(dimethylamino)phenyl]‐2‐(2,4,6‐tribromophenyl)acrylonitrile, C₁₇H₁₃Br₃N₂, ( 1 ), were obtained simultaneously by a Knoevenagel condensation between 4‐(dimethylamino)benzaldehyde and 2‐(2,4,6‐tribromophenyl)acetonitrile, and were investigated by X‐ray diffraction and density functional theory (DFT) quantum‐chemical calculations. The (Z)‐( 1 ) isomer is monoclinic (space group P2₁/n, Z′ = 1), whereas the (E)‐( 1 ) isomer is triclinic (space group P, Z′ = 2). The two crystallographically‐independent molecules of (E)‐( 1 ) adopt similar geometries. The corresponding bond lengths and angles in the two isomers of ( 1 ) are very similar. The difference in the calculated total energies of isolated molecules of (Z)‐( 1 ) and (E)‐( 1 ) with DFT‐optimized geometries is ∼4.47 kJ mol⁻¹, with the minimum value corresponding to the Z isomer. The crystal structure of (Z)‐( 1 ) reveals strong intermolecular nonvalent Br…N [3.100 (2) and 3.216 (3) Å] interactions which link the molecules into layers parallel to (10). In contrast, molecules of (E)‐( 1 ) in the crystal are bound to each other by strong nonvalent Br…Br [3.5556 (10) Å] and weak Br…N [3.433 (4) Å] interactions, forming chains propagating along [110]. The crystal packing of (Z)‐( 1 ) is denser than that of (E)‐( 1 ), implying that the crystal structure realized for (Z)‐( 1 ) is more stable than that for (E)‐( 1 ).     

一种经(E)-α-碘代烯基砜的钯催化交叉偶联反应立体选择合成(1Z,3E)-2-芳砜基取代的1,3-二烯的新方法

（E）-α-Stannylvinyl phenyl（or p-tolyl）sulfones underwent an iododestannylation reaction to afford （E）-α-iodovinyl phenyl（or p-tolyl）sulfones 1, which reacted with （E）-alkenylzirconium（IV） complexes 2 produced in situ by hydrozirconation of terminal alkynes in the presence of a Pd（PPh3）4 catalyst to afford stereoselectively （1Z,3E）-2- phenyl（or p-tolyl）sulfonyl-substituted 1,3-dienes 3 in good yields.     

Gold(I)‐Catalyzed Furan‐yne Cyclizations Involving 1,2‐Rearrangement: Efficient Synthesis of Functionalized 1‐Naphthols and Its Application to the Synthesis of Wailupemycin G

Gold‐catalyzed cascade cyclization/1,2‐rearrangement of 1‐(2‐furanyl)phenyl propargyl alcohols has been developed, which provides a rapid and efficient access to multisubstituted 1‐naphthols bearing an enal or enone moiety with high stereoselectivity. The (Z)‐ or (E)‐stereochemistry can be easily controlled by choosing protected‐ or non‐protected substrates. The utility of the methodology has been illustrated in the first total synthesis of wailupemycin G.     

Synthesis and Characterization of New (Z)‐5‐((1H‐1,2,4‐Triazol‐1‐yl)methyl)‐3‐arylideneindolin‐2‐ones

Ten compounds of new (Z)‐5‐((1H‐1,24‐triazol‐1‐yl)methyl)‐3‐arylideneindolin‐2‐ones ( 5a – j ) have been synthesized by the Knoevenagel condensation of 5‐((1H‐1,2,4‐triazol‐1‐ylmethyl)indolin‐2‐one ( 3 ) with 4‐substituted aromatic aldehydes ( 4a – j ).