Synthesis and reactivity of (C6F5)3B-N-heterocycle complexes.: 1.: Generation of highly acidic sp3 carbons in pyrroles and indoles

被引:54
作者
Guidotti, S
Camurati, I
Focante, F
Angellini, L
Moscardi, G
Resconi, L [1 ]
Leardini, R
Nanni, D
Mercandelli, P
Sironi, A
Beringhelli, T
Maggioni, D
机构
[1] Basell Polyolefins, Ctr Ric G Natta, I-44100 Ferrara, Italy
[2] Univ Bologna, Dipartimento Chim Organ A Mangini, I-40136 Bologna, Italy
[3] Univ Milan, Dipartimento Chim Inorgan Metallorgan & Anali, I-20133 Milan, Italy
[4] Univ Milan, Dipartimento Chim Sturtturale & Stereochim Inorga, I-20133 Milan, Italy
关键词
D O I
10.1021/jo020647x
中图分类号
O62 [有机化学];
学科分类号
070303 ; 081704 ;
摘要
reaction of pyrroles and indoles with B(C6F5)(3) and BCl3 produces 1:1 B-N complexes containing highly acidic sp(3) carbons, for example, N-[tris(pentafluorophenyl)borane]-5H-pyrrole (1) and N-[tris(pentafluorophenyl)borane] -3H-indole (2), that are formed by a new formal N-to-C hydrogen shift, the mechanism of which is discussed. With some derivatives, restricted rotation around the B-N bond and/or the B-C bonds was observed by NMR techniques, and some rotational barriers were calculated from experimental data. The acidity of the sp(3) carbons in these complexes is shown by their ability to protonate NEt3, with formation of pyrrolyl- and indolyl-borate ammonium salts. The driving force for this reaction is given by the restoration of the aromaticity of the heterocycle.
引用
收藏
页码:5445 / 5465
页数:21
相关论文
共 54 条
  • [1] THE DEVELOPMENT OF VERSION-3 AND VERSION-4 OF THE CAMBRIDGE STRUCTURAL DATABASE SYSTEM
    ALLEN, FH
    DAVIES, JE
    GALLOY, JJ
    JOHNSON, O
    KENNARD, O
    MACRAE, CF
    MITCHELL, EM
    MITCHELL, GF
    SMITH, JM
    WATSON, DG
    [J]. JOURNAL OF CHEMICAL INFORMATION AND COMPUTER SCIENCES, 1991, 31 (02): : 187 - 204
  • [2] SIR97:: a new tool for crystal structure determination and refinement
    Altomare, A
    Burla, MC
    Camalli, M
    Cascarano, GL
    Giacovazzo, C
    Guagliardi, A
    Moliterni, AGG
    Polidori, G
    Spagna, R
    [J]. JOURNAL OF APPLIED CRYSTALLOGRAPHY, 1999, 32 : 115 - 119
  • [3] [Anonymous], [No title captured], DOI DOI 10.1016/0021-9991(92)90277-6
  • [4] Self-consistent molecular Hartree-Fock-Slater calculations - I. The computational procedure
    Baerends, E. J.
    Ellis, D. E.
    Ros, P.
    [J]. CHEMICAL PHYSICS, 1973, 2 (01) : 41 - 51
  • [5] DENSITY-FUNCTIONAL EXCHANGE-ENERGY APPROXIMATION WITH CORRECT ASYMPTOTIC-BEHAVIOR
    BECKE, AD
    [J]. PHYSICAL REVIEW A, 1988, 38 (06): : 3098 - 3100
  • [6] Lewis acidity of tris(pentafluorophenyl) borane:: crystal and molecular structure of B(C6F5)3•OPEt3
    Beckett, MA
    Brassington, DS
    Coles, SJ
    Hursthouse, MB
    [J]. INORGANIC CHEMISTRY COMMUNICATIONS, 2000, 3 (10) : 530 - 533
  • [7] Aqua, alcohol, and acetonitrile adducts of tris(perfluorophenyl)borane: Evaluation of Bronsted acidity and ligand lability with experimental and computational methods
    Bergquist, C
    Bridgewater, BM
    Harlan, CJ
    Norton, JR
    Friesner, RA
    Parkin, G
    [J]. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2000, 122 (43) : 10581 - 10590
  • [8] 1H and 19F NMR investigation of the reaction of B(C6F5)3 with water in toluene solution
    Beringhelli, T
    Maggioni, D
    D'Alfonso, G
    [J]. ORGANOMETALLICS, 2001, 20 (23) : 4927 - 4938
  • [9] Solution and solid-state characteristics of imine adducts with tris(pentafluorophenyl)borane
    Blackwell, JM
    Piers, WE
    Parvez, M
    McDonald, R
    [J]. ORGANOMETALLICS, 2002, 21 (07) : 1400 - 1407
  • [10] Cationic Group 4 metallocene complexes and their role in polymerisation catalysis: The chemistry of well defined Ziegler catalysts
    Bochmann, M
    [J]. JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS, 1996, (03): : 255 - 270