Thermal and microwave-assisted synthesis of Diels-Alder adducts of [60]fullerene with 2,3-pyrazinoquinodimethanes: Characterization and electrochemical properties

被引:57
作者
FernandezPaniagua, UM
Illescas, B
Martin, N
Seoane, C
delaCruz, P
delaHoz, A
Langa, F
机构
[1] UNIV CASTILLA LA MANCHA, FAC QUIM, DEPT QUIM ORGAN, TOLEDO, SPAIN
[2] UNIV COMPLUTENSE MADRID, FAC QUIM, DEPT QUIM ORGAN, E-28040 MADRID, SPAIN
关键词
D O I
10.1021/jo9701344
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
[4+2] Cycloaddition reactions of six-membered heterocyclic o-quinodimethanes, generated ''in situ'' from pyrazine derivatives, to [60]fullerene, either under thermal or microwave irradiation are described. Other microwave assisted cycloadditions involving o-quinodimethanes derived from thiophene were also performed. A comparative study of the activation energy for the boat-to-boat conformational inversion has been carried out by dynamic NMR experiments, the Delta G(double dagger) values being highly dependent on the nature of the covalently attached heterocyclic systems. Theoretical calculations predict a more planar cyclohexene ring for the five member containing cycloadducts. The cycloaddition process is controlled by the HOMO of the heterocyclic o-quinodimethanes showing a LUMO(C-60)-HOMO(diene) energy differences typical for favoured cycloadditions. The redox properties of the novel organofullerenes have been determined by cyclic voltammetry in solution, showing a cathodically shifted first reduction potential values, related to [60]fullerene. Compound 15c bearing two cyano groups exhibited an opposite trend which was accounted for by the lower LUMO energy determined by semiempirical calculations.
引用
收藏
页码:3705 / 3710
页数:6
相关论文
共 47 条
  • [31] RECENT ADVANCES IN ORTHO-QUINODIMETHANE CHEMISTRY
    MARTIN, N
    SEOANE, C
    HANACK, M
    [J]. ORGANIC PREPARATIONS AND PROCEDURES INTERNATIONAL, 1991, 23 (02) : 237 - &
  • [32] MATTAY J, 1996, FULL 96 OXF UK JUL
  • [33] MEIER MS, 1995, CHEM FULLERENES, pCH10
  • [34] APPLICATIONS OF MICROWAVE DIELECTRIC HEATING EFFECTS TO SYNTHETIC PROBLEMS IN CHEMISTRY
    MINGOS, DMP
    BAGHURST, DR
    [J]. CHEMICAL SOCIETY REVIEWS, 1991, 20 (01) : 1 - 47
  • [35] Motorina IA, 1996, SYNLETT, P389
  • [36] HETERO-DIELS-ALDER REACTION OF FULLERENE - SYNTHESIS OF THIOCHROMAN-FUSED C-60 WITH O-THIOQUINONE METHIDE AND OXIDATION TO ITS S-OXIDES
    OHNO, M
    KOJIMA, S
    SHIRAKAWA, Y
    EGUCHI, S
    [J]. TETRAHEDRON LETTERS, 1995, 36 (38) : 6899 - 6902
  • [37] OHNO M, 1995, HETEROCYCL COMMUN, V1, P125
  • [38] Quinone-type methanofullerene acceptors: Precursors for organic metals
    Ohno, T
    Martin, N
    Knight, B
    Wudl, F
    Suzuki, T
    Yu, HN
    [J]. JOURNAL OF ORGANIC CHEMISTRY, 1996, 61 (04) : 1306 - 1309
  • [39] SYNTHESIS AND X-RAY STRUCTURE OF A DIELS-ALDER ADDUCT OF C-60
    RUBIN, Y
    KHAN, S
    FREEDBERG, DI
    YERETZIAN, C
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1993, 115 (01) : 344 - 345
  • [40] Sandstrom J., 1982, DYNAMIC NMR SPECTROS, P96