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Volumn 137, Issue 14, 2015, Pages 4865-4873

Aminotrifluoromethylation of Olefins via Cyclic Amine Formation: Mechanistic Study and Application to Synthesis of Trifluoromethylated Pyrrolidines

Author keywords

[No Author keywords available]

Indexed keywords

CATALYSTS; CHEMICAL REACTIONS; CHEMICAL SHIFT; COORDINATION REACTIONS; COPPER; CYCLIZATION; FLUORINE; IONIC LIQUIDS;

EID: 84927916096     PISSN: 00027863     EISSN: 15205126     Source Type: Journal    
DOI: 10.1021/jacs.5b02046     Document Type: Article
Times cited : (118)

References (147)
  • 19
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    • Lu, P. Tetrahedron 2010, 66, 2549
    • (2010) Tetrahedron , vol.66 , pp. 2549
    • Lu, P.1
  • 112
    • 84927915141 scopus 로고    scopus 로고
    • note
    • Although TEMPO is sometimes used for radical trapping in olefin trifluoromethylations with 1, it can react with 1 in the absence of substrates, giving trifluoromethylated TEMPO. See refs 5a, 21d and Supporting Information.
  • 123
    • 84927938609 scopus 로고    scopus 로고
    • note
    • Solubility of CuI and also Cu2(O2CAr)4·2MeOH is low, and thus complexation with substrates was expected to affect the reactivity by increasing the solubility.
  • 124
    • 84927942688 scopus 로고    scopus 로고
    • note
    • Almost no byproduct was detected under the conditions used. For experimental procedure, see Supporting Information.
  • 125
    • 84927947129 scopus 로고    scopus 로고
    • note
    • For details of the preparation, see Supporting Information.
  • 127
    • 84927946290 scopus 로고    scopus 로고
    • note
    • Use of THF as the solvent completely stopped the reaction. Details were reported in our previous work (Supporting Information of ref 19a)
  • 132
    • 84927922760 scopus 로고    scopus 로고
    • note
    • Upon generation of Cu(II) species from CuI and 1 during the preincubation, CF3 radical should also be generated, but in the absence of substrate it is likely to decompose. Further discussions are described in Supporting Information.
  • 133
    • 84927917452 scopus 로고    scopus 로고
    • note
    • Weakly coordinating MeOH derived from 5a may affect the chemical shift and also the reactivity of the catalyst due to its participation in the dynamic equilibrium.
  • 135
    • 84927942781 scopus 로고    scopus 로고
    • note
    • The structure was decided by analogy with the X-ray single-crystal structure of [Zn(1)2(4-NO2C6H4CH2OH)2(H2O)2](NTf2)2 reported by Togni. For details, see ref 21a.
  • 136
    • 84927923894 scopus 로고    scopus 로고
    • note
    • DFT calculation of Togni reagent indicated that the carbonyl oxygen makes a major electronic contribution to the HOMO. Thus we show the structures with carbonyl coordination. For details, see Supporting Information.
  • 137
    • 84927929567 scopus 로고    scopus 로고
    • note
    • A dimeric Cu species (m/z = 1182.5563) was also detected and assigned as complex D shown below. The complex is also a potential reactive species, but the monomeric species were considered as the major catalytically active species on cycle for the reasons discussed in the text.
  • 138
    • 84927928192 scopus 로고    scopus 로고
    • note
    • At the late stage of the reaction, increased acidity due to 2-iodobenzoic acid production may affect the chemical shift of the signal derived from the aziridine 3.
  • 139
    • 84927921284 scopus 로고    scopus 로고
    • note
    • The presented data suggested the Cu(II) species as a Lewis acid catalyst mainly contributed in the reaction with the pretreated CuI. If CF3 radical was generated by the oxidation of CuI in the presence of the substrate, it may partly contribute to the production of 3. Further discussion is shown in Supporting Information.
  • 140
    • 84927927339 scopus 로고    scopus 로고
    • note
    • ESI-MS of the reaction mixture and assignment of the signals are described in Supporting Information; a Cu species coordinating Togni reagent 1, the substrate, and/or the aziridine was detected.
  • 141
    • 84927915217 scopus 로고    scopus 로고
    • note
    • In the conversion from TS to IV, C-I and C-N bond formation may proceed either in concerted or stepwise mechanism via cation intermediate formation.
  • 145
    • 84927925316 scopus 로고    scopus 로고
    • note
    • In the absence of Et3N, several unidentified products were also obtained in addition to the uncyclized allylic and hydrotrifluoromethylation products.41 Et3N improved the product selectivity of the reaction.
  • 146
    • 84927925090 scopus 로고    scopus 로고
    • note
    • For details of additive screening and optimization, see Supporting Information.
  • 147
    • 84927926052 scopus 로고    scopus 로고
    • note
    • The stereochemical outcome may suggest the stepwise mechanism for the pyrrolidine formation.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.