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Cyclobutene-1,2-dione

Tributylstannyl)-3-cyclobutene-1,2-diones and 4-methyl-3-(tributylstan-nyl)-3-cyclobutene-l,2-dione 2-ethylene acetals undergo the palladium/copper-catalyzed cross coupling with acyl halides, and palladium-catalyzed carbon-ylative cross coupling with aryl/heteroaryl iodides [45]. The coupling reaction of alkenyl (phenyl )iodonium triflates is also performed by a palladium/copper catalyst [46],... [Pg.121]

Diethoxy-3-cyclobutene-1,2-dione is commercially available from Aldrich Chemical Company, Inc. Caution This substance was found to cause severe skin rashes, and extreme care should be exercised in handling it.. The dimethoxy analog appears to be safer. Diethyl squarate has the following spectral properties IR (neat) cm- 1830, 1741, and 1609 H NMR (CDCI3, 300 MHz) 8 1.47 (t, 6 H. J = 2.9), 4.47 (q, 4 H, J = 7.1). [Pg.222]

Diethyl squarate Cyclobutenedione, diethoxy- (8) 3-Cyclobutene- 1,2-dione, 3,4-diethoxy- (9) (5231-87-8)... [Pg.225]

Even in such molecules with large ground state dipole moment, we observed the production of non-centrosymmetric crystal structures exhibiting SHG by introduction of asymmetric amino acid derivatives into the cyclobutenedione. (-)4-(4,-dimethylaminophenyl)-3-(2l-hydroxypropylamino) cyclobutene-1,2-dione (DAD) (3), (+)4-(4 -di-... [Pg.337]

Figure 2. UV spectra of 4-(4 -methylphenyl)-3-hydroxy-cyclobutene- 1,2-dione. — in CH2CI2, — in C2H5OH soln. Figure 2. UV spectra of 4-(4 -methylphenyl)-3-hydroxy-cyclobutene- 1,2-dione. — in CH2CI2, — in C2H5OH soln.
Figure 3. Molecular structure of (-)4-(4,-dimethylamino-phenyl)-3-(21-hydroxypropylamino)cyclobutene-1,2-dione (DAD), as determined by X-ray crystallography. Figure 3. Molecular structure of (-)4-(4,-dimethylamino-phenyl)-3-(21-hydroxypropylamino)cyclobutene-1,2-dione (DAD), as determined by X-ray crystallography.
Palladium(II)-copper(I) cocatalyzed couplings of several (/ ,/ -dialkylvinyl)phenyliodo-nium triflates with 4-isopropoxy-3-tri- -butylstannyl-3-cyclobutene-l,2-dione (71) in DMF at room temperature have recently been described (equation 259)157. As observed in earlier studies of Cu(I)- or Pd(II)-promoted reactions of vinyliodonium salts, the vinyl ligands are introduced with retention of configuration. Since iodobenzene is a byproduct of ligand coupling, the production of 3-phenyl-4-isopropoxy-3-cyclobutene-1,2-dione might also be expected. However, the (/ ,/ -dialkylvinyl)iodonium ions are much more reactive... [Pg.1268]

ETHENYL-4-METHOXYCYCLOBUTENE-1,2-DIONE 3-CYCLOBUTENE-1,2-DIONE, 3-ETHENYL-4-METHOXY- (124022-02-2), 76, 189... [Pg.160]

Squaric acid 3-Cyclobutene-1,2-dione, 3,4-dihydroxy- (2892-51-5), 76, 190 Stannanes, chiral a-alkoxyallylic, 77, 103 Stereochemical purity, determination of, 76, 52... [Pg.169]

Bromopropene Propene, 2-bromo- (8) 1-Propene, bromo- (9) (557-93-7) tert-Butyllithium Lithium, tert-butyl- (8) Lithium, (1,1-dimethylethyl)- (9) (594-19-4) Diisopropyl squarate 3-Cyclobutene-1,2-dione, 3,4-bis(1-methylethoxy)- (10) (61999-62-5)... [Pg.175]

Kinney WA, Abou-Gharbia M, Garrison DT, Schmid J, Kowal DM, Bramlett DR, Miller TL, Tasse RP, Zaleska MM, Moyer JA. Design and synthesis of (2-(8,9-dioxo-2,6-diazabicyclo(5.2.0. non-l(7.-en-2-yl.- ethyl.phosphonic acid (EAA-090., a potent N-methyl-D-aspartate antagonist, via the use of 3-cyclobutene-1,2-dione as an achiral a-amino acid bioisostere. J. Med. Chem. 1998 41 236-246. [Pg.2045]

C4H204 3,4-dihydroxy-3-cyclobutene-1,2-dione 2892-51-5 25.00 1.4720 2 2631 C4H5Br04 DL-bromosuccinic acid 923-06-8 25.00 1.7770 2... [Pg.212]

C10H14O 3-tert-butyl phenol 585-34-2 22.18 0.9688 2 20160 C10H14O4 3,4-diisopropoxy-3-cyclobutene-1,2-dione 61699-62-5 23.57 1.0891 2... [Pg.253]

Gatti, C., May, E., Destro, R. and Cargnoni, F. (2002) Fundamental properties and nature of C-H- O interactions in crystals on the basis of experimental and theoretical charge densities. The case of 3,4-bis(dimethylamino)-3- cyclobutene-1,2-dione (DMACB) crystal, J. Phys. Chem. A 106, 2707-2720. [Pg.242]

Disubstituted cyclobutene-1,2-diones." These products can be prepared by reaction of 3,4-dichlorocyclobutene-l,2-dioncs with functionalized organocopper/zinc reagents. [Pg.222]

DIMETHYL SQUARATE AND ITS CONVERSION TO 3-ETHENYL-4-METHOXYCYCLOBUTENE-1,2-DIONE AND 2-BUTYL-6-ETHENYL-5-M ETHOXY-1,4-BENZOQUINONE (3-Cyclobutene-1,2-dione, 3-ethenyl-4-methoxy- and 2,5-cyclohexadiene-1,4-dione, 5-butyl-3-ethenyl-2-methoxy- from 3-cyclobutene-1,2-dione, 3,4-dimethoxy-)... [Pg.189]

Ethenyl-4-methoxycyclobutene-1,2-dione 3-Cyclobutene-1,2-dione, 3-ethenyl-4-methoxy- (12) (124022-02-2)... [Pg.198]

See other pages where Cyclobutene-1,2-dione is mentioned: [Pg.796]    [Pg.110]    [Pg.419]    [Pg.796]    [Pg.333]    [Pg.337]    [Pg.55]    [Pg.141]    [Pg.159]    [Pg.222]    [Pg.437]    [Pg.496]    [Pg.514]    [Pg.796]    [Pg.416]    [Pg.144]    [Pg.234]   


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3-Cyclobutene-l,2-diones

3.4- Dihydroxy-3-cyclobutene-l,2-dione

3.4- diamino-3-cyclobutene-l,2-dione

3.4- dichloro-3-cyclobutene-l,2-dione

Cyclobutene

Cyclobutene-1,2-dione 3,4-dimethyl

Cyclobutene-diones

Cyclobutenes

DIMETHYL SQUARATE: 3-CYCLOBUTENE-1,2-DIONE, 3,4-DIMETHOXY

Diamino-cyclobutene-diones

Diethyl squarate: 3-Cyclobutene-1,2-dione, 3,4-diethoxy

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