.beta.-Scission of 9-decalinoxyl and related free radicals

Macdonald, Timothy L.; O'Dell, Dale E.

doi:10.1021/jo00320a057

Cited by 22 publications

(9 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1 H NMR (300 MHz, CDCl 3 ): δ =7.19–7.01 (m, 5 H), 5.86–5.83 (m, 1 H), 5.49–5.43 (m, 1 H), 4.58 (dt, J =2.3, 5.2 Hz, 2 H), 3.50–3.46 (m, 2 H); 13 C NMR (75 MHz, CDCl 3 ): δ =158.7, 136.1, 128.8, 127.8, 127.3, 125.7, 124.0, 121.4, 71.2, 31.8; IR (film): $\tilde \nu$ = 2931, 2882, 1724, 1602, 1583, 1489, 1455, 1230, 1062, 761 cm −1 ; MS: m / z (%): 146 (100) [ M ] + , 131 (59), 127 (32), 115 (34), 103 (10), 91 (25), 89 (13), 77 (17), 72 (4), 63 (17), 51 (22), 39 (23), 27 (7). The analytical data were in agreement with those reported in the literature 31…”

Section: Methodssupporting

confidence: 90%

Evidence for the Formation of Singly Bonded Dimers During the Reductive Electrochemistry of Methanofullerenes

Oçafrain¹,

Herranz²,

Marx³

et al. 2003

Chemistry A European J

View full text Add to dashboard Cite

Four methanofullerene derivatives, with phosphonate or sulfone groups attached to a C(60) core through a Bingel procedure, were synthesized to probe their stability upon electrolytic reduction. Derivatives 1 and 2 are the most stable upon electroreduction and do not exhibit retro-cyclopropanation reactions until more than three electrons per C(60) derivative are transferred. The cyclopropane ring is then removed and C(60)(>CH(2))(n) (n=1-3) products result from reactions of the trianion of C(60) with the solvent, CH(2)Cl(2). The situation with diphosphonate 3 or phosphonatecarboxylate 4 is dramatically different. For 3, quantitative retro-cyclopropanation occurs when 2.8 e(-) per molecule are transferred. In the case of 4, when more than two electrons per molecule are transferred, there is evidence of the reversible formation of a very stable intermediate, which is oxidized at a potential 500 mV more positive than the first fullerene-based reduction of the parent compound. Electrolysis of a simple C(70)-Bingel monoadduct (5) also exhibits the formation of a similar intermediate. On the basis of cyclic voltammetry, ESR spectroscopy, and MALDI analysis of products, the intermediate observed during the electrolysis of compounds 4 and 5 is assigned to a dimeric structure.

show abstract

Section: Methodssupporting

confidence: 90%

Evidence for the Formation of Singly Bonded Dimers During the Reductive Electrochemistry of Methanofullerenes

Oçafrain¹,

Herranz²,

Marx³

et al. 2003

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…The analytical data were in agreement with those reported in the literature. [31] Eleven other compounds displayed in Table 2 have been prepared analogously. Their analytical and spectroscopic data were in agreement with those reported in the literature: 10, [32] 12, [33] 14, [34] 17, [35] 21, [38] 23, [38] 25, [39] 31, [40] 33, [13] 39, [42] 45, [16] 47, [43] 49, [19] 51, [19] 53, [9] 55, [15] (14), 29 (16) …”

Section: Methodsmentioning

confidence: 99%

Indenylidene Complexes of Ruthenium: Optimized Synthesis, Structure Elucidation, and Performance as Catalysts for Olefin Metathesis—Application to the Synthesis of the ADE-Ring System of Nakadomarin A

et al. 2001

View full text Add to dashboard Cite

An optimized and large scale adaptable synthesis of the ruthenium phenylindenylidene complex 3 is described which employs commercially available diphenyl propargyl alcohol 5 as a stable and convenient carbene source. Previous ambiguities as to the actual structure of the complex have been ruled out by a full analysis of its NMR spectra. A series of applications to ring closing metathesis (RCM) reactions shows that complex 3 is as good as or even superior to the classical Grubbs carbene 1 in terms of yield, reaction rate, and tolerance towards polar functional groups. Complex 3 turns out to be the catalyst of choice for the synthesis of the enantiopure core segment 77 of the marine alkaloid nakadomarin A 60 comprising the ADE rings of this target. Together with a series of other examples, this particular application illustrates that catalyst 3 is particularly well suited for the cyclization of medium-sized rings by RCM. Other key steps en route to nakadomarin A are a highly selective intramolecular Michael addition setting the quaternary center at the juncture of the A and D rings and a Takai-Nozaki olefination of aldehyde 73 with CH2I2, Ti(OiPr)4 and activated zinc dust.

show abstract

“…calcd C 59. Compounds 19,[32] 21, [33] 23, [34] 25 [35] and 27 [36] were prepared analogously. Compounds 19,[32] 21, [33] 23, [34] 25 [35] and 27 [36] were prepared analogously.…”

Section: Representative Procedures For Rcmmentioning

confidence: 99%

Cationic Ruthenium Allenylidene Complexes as Catalysts for Ring Closing Olefin Metathesis

et al. 2000

View full text Add to dashboard Cite

A series of well accessible cationic ruthenium allenylidene complexes of the general type [(eta6-arene)(R3P)RuCl(=C=CR'2)]+ X- is described which constitute a new class of pre-catalysts for ring closing olefin metathesis reactions (RCM) and provide an unprecedented example for the involvement of metal allenylidenes in catalysis. They effect the cyclization of various functionalized dienes and enynes with good to excellent yields and show a great tolerance towards an array of functional groups. Systematic variations of their basic structural motif have provided insights into the essential parameters responsible for catalytic activity which can be enhanced further by addition of Lewis or Bronsted acids, by irradiation with UV light, or by the adequate choice of the "non-coordinating" counterion X-. The latter turned out to play a particularly important role in determining the rate and selectivity of the reaction. A similarly pronounced influence is exerted by remote substituents on the allenylidene residue which indicates that this ligand (or a ligand derived thereof) may remain attached to the metal throughout the catalytic process. X-ray crystal structures of the catalytically active allenylidene complexes 3b.PF6 and 15.OTf as well as of the chelate complex 10 required for the preparation of the latter catalyst are reported.

show abstract

.beta.-Scission of 9-decalinoxyl and related free radicals

Cited by 22 publications

References 0 publications

Evidence for the Formation of Singly Bonded Dimers During the Reductive Electrochemistry of Methanofullerenes

Evidence for the Formation of Singly Bonded Dimers During the Reductive Electrochemistry of Methanofullerenes

Indenylidene Complexes of Ruthenium: Optimized Synthesis, Structure Elucidation, and Performance as Catalysts for Olefin Metathesis—Application to the Synthesis of the ADE-Ring System of Nakadomarin A

Cationic Ruthenium Allenylidene Complexes as Catalysts for Ring Closing Olefin Metathesis

Contact Info

Product

Resources

About