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Norbornadiene

About: Norbornadiene is a research topic. Over the lifetime, 2389 publications have been published within this topic receiving 38603 citations.


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Journal ArticleDOI
TL;DR: In this article, the copper(III) and copper(II) benzoate complexes in pyridine gave the corresponding 7-benzoyloxy derivatives, and the proposed mechanism suggests two single-electron oxidations by copper (III and/or copper (II).
Abstract: Oxidation of norbornadiene and benzonorbornadiene by copper(III) and copper(II) benzoate complexes in pyridine gave the corresponding 7-benzoyloxy derivatives. The proposed mechanism suggests two single-electron oxidations by copper(III) and/or copper(II).

1 citations

01 Jan 1982
TL;DR: In this article, the structure of Ph2PS2N3 (R = Me, Ph, OPh) has been determined by X-ray crystallography and the structure was solved by direct methods and refined by Fourier and full-matrix least-squares techniques, and all nonhydrogen atoms were refined anisotropically to give a final R = 0.047 and R, =0.077 for 1471 reflections with I > 341.
Abstract: The reaction of R2PPR2 (R = Me, Ph) or (Ph0)3P with S4N4 in toluene at reflux produces cyclo-1X5-phospha- 3,5-dithia-2,4,6-triazenes R2PS2N3 (R = Me, Ph, OPh), the cyclic structures of which have been confirmed by I5N NMR spectroscopy. The crystal and molecular structure of Ph2PS2N3 has been determined by X-ray crystallography. The crystals of Ph2PS2N3 are monoclinic, space group PZI/c, a = 8.305 (1) A, b = 13.183 (2) A, c = 12.487 (I) A, /3 = 105.53 (1)O, and Z = 4. The structure was solved by direct methods and refined by Fourier and full-matrix least-squares techniques, and all nonhydrogen atoms were refined anisotropically to give a final R = 0.047 and R, = 0.077 for 1471 reflections with I > 341). The structure consists of a 6-membered PS2N3 ring in which the five-atom sequence NSNSN is coplanar to within 0.05 A, while the phosphorus atom is 0.284 (I) 8, out of this plane. The S-N bond lengths are within the range 1.560 (3)-1.583 (5) A, while the mean P-N bond length is 1.623 (4) A. The angles at phosphorus are LPCndo = 115.8 (2)O and LP,,, = 107.1 (2)'. Ab initio HartreeFock-Slater SCF calculations on the model compound H2PS2N3 show that (a) the PS2N3 ring contains eight R electrons largely delocalized over the NSNSN sequence, (b) contributions from 3d orbitals on phosphorus have an important stabilizing influence on the antibonding T* MOs (c) the strong visible absorption band at 550-580 nm in R2PS2N3 (R = Me, Ph, OPh) can be assigned to a HOMO(a*) - LUMO(r*) transition (calculated wavelength ca. 560 nm), and (d) the experimental geometry of the PS2N, ring (as observed in Ph2PS2N3) is slightly lower in energy (ca. 15 kcal mol-)) than that of a planar PS2N3 ring. The phosphadithiatriazenes readily form adducts of the type R2PS2N,C,H, with norbornadiene. The crystal and molecular structure of Ph2PS2N3.C7H8 has been determined by X-ray crystallography. The crystals are triclinic, space group P1, a = 9.239 (1) A, b = 6.284 (1) A, c = 9.314 (1) A, (Y = 76.98 (l)', /3 = 118.98 (l)', y = 110.08 (I)', and Z = 1. The structure was solved by direct methods and refined by Fourier and full-matrix least-squares procedures, and all nonhydrogen atoms were refined anisotropically to give a final R = 0.046 and R, = 0.063 for 1583 reflections with I > 348. The structural determination confirms the 'H and I3C NMR evidence that the cycloaddition of norbornadiene to Ph2PS2N, occurs in a 1,3 fashion across the two sulfur atoms to give the exo-/3 isomer of the adduct. As a result of the addition, the central N atom of the NSNSN unit is displaced by 0.817 (6) 8, from the plane of the central S2N2 unit, which is planar to within 0.01 A. The S-N bond lengths are 1.61-1.64 A, the lengthening being attributed primarily to the rupture of the R system. The cycloaddition can be regarded as a symmetry-allowed (8, + 2,) reaction, and the preference for S,S addition can be readily understood from consideration of the eigenvector coefficients of the HOMO and LUMO of the PS2N, ring.

1 citations

Journal ArticleDOI
TL;DR: In this article, cycloaddition reactions of norbornadiene with fluorinated heteroaddends (hexafluoro-acetone, dichlorotetrafluoroacetone and trifluoroacetonitrile) were studied.
Abstract: Cycloaddition reactions of norbornadiene with fluorinated heteroaddends (hexafluoro-acetone, dichlorotetrafluoroacetone, trifluoroacetonitrile, and N-trifluoroacetylhexafluoro-propan-2-imine) were studied. As a rule, the reactions follow the concerted mechanism. The reaction with bis(trifluoromethyl)ketene gave a mixture of tricyclene [2+2]- and [2+2+2]-cyclo-adducts formed along different pathways.

1 citations

Journal ArticleDOI
TL;DR: The first practical asymmetric version of the intermolecular Pauson-Khand reaction has been developed based on novel chiral (non-racemic) alkoxy acetylene dicobalt hexacarbonyl complexes as mentioned in this paper.
Abstract: The first practical asymmetric version of the intermolecular Pauson-Khand reaction has been developed based on novel chiral (non-racemic) alkoxy acetylene dicobalt hexacarbonyl complexes. The major adduct from (1R, 2S)-2-phenylcyclohexyloxyethyne and norbornadiene, isolated in 58% yield, is shown to be useful for obtaining chiral 4-substituted 2-cyclopentenones.

1 citations

Journal Article
01 Jan 1985-Chimia
TL;DR: When treated with BuLi and Me3CONa, both norbornadiene and norbornene underwent a H/Na exchange at the 2-position as mentioned in this paper, and cycloheptatriene reacted approx. 30 times faster with Me3SiCl.
Abstract: When treated with BuLi and Me3CONa, both norbornadiene and norbornene underwent a H/Na-exchange at the 2-position. The diene, however, reacted approx. 30 times faster with Me3SiCl. Bicyclo[3.2.0]hepta-2,6-diene was also more readily metalated than bicyclo[3.2.0]hept-6-ene and its 7-position was preferentially attacked. Under the same conditions, cycloheptatriene was silylated at the 2-position only. [on SciFinder (R)]

1 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
202316
202240
202133
202040
201930
201829