The Rearrangement of 1-para-Substituted Phenyl-1-cyclopropylethylenes

Ketley, A. D.; McClanahan, James L.

doi:10.1021/jo01014a508

Cited by 22 publications

(16 citation statements)

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“…Molecular Orbital Calculations. All computations were done on an Apple Macintosh Ilfx with use of MOP AC version 6.00 (QCPE No. 455) revised as version 6.02 for Apple Macintosh.6 The calculations were carried out by the restricted Hartree-Fock (RHF) method and the PM3 Hamiltonian.…”

Section: Methodsmentioning

confidence: 99%

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Radical ring-opening polymerization of .alpha.-cyclopropylstyrenes. Polymerization behavior and mechanistic aspects of polymerization by the molecular orbital method

Sanda¹,

Takata²,

Endō³

1993

Macromolecules

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Synthesis and radical polymerization of substituted a-cyclopropylstyrenes [l-(4-substituted phenyl)-1-cyclopropylethylene; 3a (X = OMe), 3b (X = H), and 3c (X = Cl)] were carried out. 3a-c were prepared by the Wittig reaction of the corresponding cyclopropyl aryl ketones. The radical polymerization of 3 was performed in the presence of an appropriate radical initiator (3 mol % vs monomer) at 60-120 O C . The molecular weight of the polymer obtained decreased while the conversion of the monomer increased, as the polymerization temperature rose. The structure of the polymer was determined to consist only of the unit formed by selective 1,5-ring-opening polymerization. The ratio of the observed rates of polymerization was estimated to be 3c:3a:3b = 2.0:1.61. The effect of a para substituent on the rate of polymerization was not the same as that of para substituted styrenes. The electron density of vinyl 8-carbon of 3 decreased in the following order: 3a > 3b > 3c, being the same as that of para substituted styrenes from 13C NMR analysis and molecular orbital calculation. The rate of polymerization was suggested to be affected by the polarity of the monomers (3). The dipole moment as an index of polarity well explained the order of the rate of polymerization. 3 showed shrinkage similar to those of common cyclic monomers with similar molecular weights; 7.23-8.56%. This value was consistent with the occurrence of the selective radical ring-opening polymerization of 3. T g of the polymers (4) obtained was lower by 94-102 O C than corresponding poly-(para-substituted styrenels.

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Section: Methodsmentioning

confidence: 99%

“…Volume Change on the Radical Polymerization of Measured by density gradient tubes at 25 °C 6. [Density(monomer) -density(polymer)]/density (monomer) x 100.e Run 3 in TableI.…”

mentioning

confidence: 99%

Radical ring-opening polymerization of .alpha.-cyclopropylstyrenes. Polymerization behavior and mechanistic aspects of polymerization by the molecular orbital method

Sanda¹,

Takata²,

Endō³

1993

Macromolecules

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“…The tube was transferred back into the glovebox, and the solution was lyophilized, dissolved into pentane and stuck in the freezer to yield 74.5 mg (74.7%) of yellow crystals. 1 Synthesis of α-cyclopropyl styrene (8) 30 Prepared by a modification of literature procedure. 27 To a 50 mL round bottom flask in the glovebox was added 4.110 g of methyl triphenylphosphonium bromide (11.51 mmol), 1.286 g of potassium tert-butoxide (11.48 mmol), and ca.…”

Section: Synthesis Of (N 3 N)tin(bn)c(h)=pph (5)mentioning

confidence: 99%

Radical Hydrophosphination Initiated by Triamidoamine-Supported Titanium Despite Insertion into the Ti–P Bond

Seth

Waterman

2023

Preprint

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Titanium compounds supported by the triamidoamine ligand (N3N, N(CH2CH2NSiMe33–)3) have been investigated for hydrophos-phination catalysis. The simple titanium alkyl compound (N3N)TiMe (2) demonstrate modest activity as a precatalyst for the pho-tocatalytic hydrophosphination of styrene, but the terminal phosphido compound, (N3N)TiPHPh (4), is inactive. Analysis of these reactions by EPR spectroscopy indicates that (N3N)TiMe undergoes homolytic Ti–C bond cleavage to achieve radical hydrophos-phination. This pathway was further supported in a radical trapping experiment. The phosphido derivative 4 does not produce rad-icals under similar conditions, despite undergoing facile migratory insertion reactions with polar substrates featuring C–N and C–O multiple bonds. Both nitrile and isonitrile substrates insert with ultimate formation of phosphaalkene products, a change in reactivi-ty as comparted to the zirconium congener. Molecular structures of (N3N)TiPHPh (4), (N3N)TiNBnC=PPh (5), and (N3N)TiN(H)C(Ph)=PPh (6) are reported.

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“…This is a known compound [CAS: 829-17-4] and prepared according to the general procedure A (844 mg, yield: 97%), chromatography on silica gel (petroleum ether/EtOAc = 97:3, v/v). 1 H NMR (400 MHz, CDCl 3 ) δ = 7.59 (d, J = 7.9 Hz, 2H), 6.92 (d, J = 7.9 Hz, 2H), 5.25 (s, 1H), 4.90 (s, 1H), 3.86 (s, 3H), 1.69–1.65 (m, 1H), 0.86 (d, J = 7.1 Hz, 2H), 0.63 (s, 2H).…”

Section: Experimental Sectionmentioning

confidence: 99%

Difluoroalkylation/C–H Annulation Cascade Reaction Induced by Visible-Light Photoredox Catalysis

Chen

Jiao

et al. 2016

J. Org. Chem.

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We report the first example of difluoroalkylation/C-H annulation cascade reactions of cyclopropyl olefins induced by visible-light photoredox catalysis regioselectively affording partially hydrogenated naphthalenes and quinolines with a variety of difluorinated side chains. The alkylation reagent could be extended to monofluoro and trifluoro reagents, nitrile and malonate. The regioselectivity was investigated by means of density functional theory calculations.

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The Rearrangement of 1-para-Substituted Phenyl-1-cyclopropylethylenes

Cited by 22 publications

References 0 publications

Radical ring-opening polymerization of .alpha.-cyclopropylstyrenes. Polymerization behavior and mechanistic aspects of polymerization by the molecular orbital method

Radical ring-opening polymerization of .alpha.-cyclopropylstyrenes. Polymerization behavior and mechanistic aspects of polymerization by the molecular orbital method

Radical Hydrophosphination Initiated by Triamidoamine-Supported Titanium Despite Insertion into the Ti–P Bond

Difluoroalkylation/C–H Annulation Cascade Reaction Induced by Visible-Light Photoredox Catalysis

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