메뉴 건너뛰기




Volumn 65, Issue 33, 2009, Pages 6549-6570

Palladium-catalyzed alkene carboamination reactions for the synthesis of substituted piperazines

Author keywords

[No Author keywords available]

Indexed keywords

ALKENE; ALKENYL HALIDE; ALLYLAMINE; AMINO ACID; CARBON; ETHYLENEDIAMINE DERIVATIVE; FUNCTIONAL GROUP; HETEROCYCLIC COMPOUND; NITROGEN; PALLADIUM; PIPERAZINE DERIVATIVE; TETRAHYDROQUINOXALINE; UNCLASSIFIED DRUG;

EID: 67650239544     PISSN: 00404020     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tet.2009.04.017     Document Type: Article
Times cited : (28)

References (62)
  • 5
    • 67650262074 scopus 로고    scopus 로고
    • For syntheses of nonracemic 2,6-dialkylpiperazines, see
    • For syntheses of nonracemic 2,6-dialkylpiperazines, see:
  • 9
    • 67650246730 scopus 로고    scopus 로고
    • For syntheses of racemic 2,6-dialkylpiperazines, see
    • For syntheses of racemic 2,6-dialkylpiperazines, see:
  • 12
    • 38749153968 scopus 로고    scopus 로고
    • Michael has recently described a concise, highly diastereoselective asymmetric synthesis of trans-2,6-disubstituted piperazines bearing C-2 methyl groups that is complementary to the transformations described in this paper. See:
    • Michael has recently described a concise, highly diastereoselective asymmetric synthesis of trans-2,6-disubstituted piperazines bearing C-2 methyl groups that is complementary to the transformations described in this paper. See:. Cochran B.M., and Michael F.E. Org. Lett. 10 (2008) 329-332
    • (2008) Org. Lett. , vol.10 , pp. 329-332
    • Cochran, B.M.1    Michael, F.E.2
  • 16
    • 34548185689 scopus 로고    scopus 로고
    • A portion of these studies have been previously communicated. See:
    • A portion of these studies have been previously communicated. See:. Nakhla J.S., and Wolfe J.P. Org. Lett. 9 (2007) 3279-3282
    • (2007) Org. Lett. , vol.9 , pp. 3279-3282
    • Nakhla, J.S.1    Wolfe, J.P.2
  • 17
    • 67650213537 scopus 로고    scopus 로고
    • For related Pd-catalyzed carboamination reactions between aryl or alkenyl halides and alkenes bearing pendant nitrogen nucleophiles that afford pyrrolidines, isoxazolidines, pyrazolidines, indolines, or imidazoldin-2-ones, see
    • For related Pd-catalyzed carboamination reactions between aryl or alkenyl halides and alkenes bearing pendant nitrogen nucleophiles that afford pyrrolidines, isoxazolidines, pyrazolidines, indolines, or imidazoldin-2-ones, see:
  • 27
    • 67650243417 scopus 로고    scopus 로고
    • For examples of Cu-catalyzed intramolecular carboamination of N-(arylsulfonyl)-2-allylanilines and related derivatives, see
    • For examples of Cu-catalyzed intramolecular carboamination of N-(arylsulfonyl)-2-allylanilines and related derivatives, see:
  • 29
    • 2542624580 scopus 로고    scopus 로고
    • For Pd(II)-catalyzed alkoxycarbonylation of alkenes bearing tethered nitrogen nucleophiles, see:
    • Sherman E.S., Chemler S.R., Tan T.B., and Gerlits O. Org. Lett. 6 (2004) 1573-1575 For Pd(II)-catalyzed alkoxycarbonylation of alkenes bearing tethered nitrogen nucleophiles, see:
    • (2004) Org. Lett. , vol.6 , pp. 1573-1575
    • Sherman, E.S.1    Chemler, S.R.2    Tan, T.B.3    Gerlits, O.4
  • 31
    • 33746917969 scopus 로고    scopus 로고
    • For carboamination of vinylcyclopropanes, see:
    • Scarborough C.C., and Stahl S.S. Org. Lett. 8 (2006) 3251-3254 For carboamination of vinylcyclopropanes, see:
    • (2006) Org. Lett. , vol.8 , pp. 3251-3254
    • Scarborough, C.C.1    Stahl, S.S.2
  • 32
    • 84942731093 scopus 로고
    • For 1,1-carboamination of alkenes, see:
    • Larock R.C., and Yum E.K. Synlett (1990) 529-530 For 1,1-carboamination of alkenes, see:
    • (1990) Synlett , pp. 529-530
    • Larock, R.C.1    Yum, E.K.2
  • 37
    • 15944369282 scopus 로고    scopus 로고
    • Use of biphasic conditions led to significant erosion of enantiomeric purity. See:
    • Use of biphasic conditions led to significant erosion of enantiomeric purity. See:. Lu Z., and Twieg R.J. Tetrahedron Lett. 46 (2005) 2997-3001
    • (2005) Tetrahedron Lett. , vol.46 , pp. 2997-3001
    • Lu, Z.1    Twieg, R.J.2
  • 38
    • 0033564987 scopus 로고    scopus 로고
    • DEPBT=3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one. Use of other reagents (e.g., DCC/HOBT or CDI) resulted in partial epimerization to afford products with ∼85-90% ee. See:
    • DEPBT=3-(diethoxyphosphoryloxy)-1,2,3-benzotriazin-4(3H)-one. Use of other reagents (e.g., DCC/HOBT or CDI) resulted in partial epimerization to afford products with ∼85-90% ee. See:. Li H., Jiang X., Ye Y.-H., Fan C., Romoff T., and Goodman M. Org. Lett. 1 (1999) 91-94
    • (1999) Org. Lett. , vol.1 , pp. 91-94
    • Li, H.1    Jiang, X.2    Ye, Y.-H.3    Fan, C.4    Romoff, T.5    Goodman, M.6
  • 42
    • 67650258915 scopus 로고    scopus 로고
    • note
    • In order to achieve complete consumption of starting materials, a ratio of four ligands/Pd atom was employed, as 2:1 ligand/Pd ratios led to only 85-90% conversion.
  • 43
    • 67650231271 scopus 로고    scopus 로고
    • note
    • 1-pivaloyl protected substrates afforded only trace amounts of products.
  • 44
    • 67650237809 scopus 로고    scopus 로고
    • note
    • Initial studies on carboaminations of amides such as 5a-c suggest these transformations may be feasible, but further optimization is required; low yields (ca. 10-20%) of the desired products were obtained.
  • 45
    • 67650225679 scopus 로고    scopus 로고
    • For one-pot syntheses of N-aryl indolines or N-aryl pyrrolidines from primary amines or anilines bearing pendant alkenes, see
    • For one-pot syntheses of N-aryl indolines or N-aryl pyrrolidines from primary amines or anilines bearing pendant alkenes, see:
  • 46
    • 67650219179 scopus 로고    scopus 로고
    • Ref. 9b;
    • Ref. 9b;
  • 50
    • 67650225906 scopus 로고    scopus 로고
    • For additional discussion of syn- versus anti-aminopalladation of alkenes, see
    • For additional discussion of syn- versus anti-aminopalladation of alkenes, see:
  • 53
    • 67650219180 scopus 로고    scopus 로고
    • Alkene insertion into late M-H bonds is usually much faster than alkene insertion into late M-C bonds. See
    • Alkene insertion into late M-H bonds is usually much faster than alkene insertion into late M-C bonds. See:
  • 56
    • 67650249899 scopus 로고    scopus 로고
    • The insertion of alkenes into Pd-C bonds in intramolecular Heck reactions occurs through a conformation in which the alkene π-bond and the Pd-C bond are eclipsed. Other possible transition states in which the orientation of the alkene is perpendicular to the M-C bond are significantly higher in energy See
    • The insertion of alkenes into Pd-C bonds in intramolecular Heck reactions occurs through a conformation in which the alkene π-bond and the Pd-C bond are eclipsed. Other possible transition states in which the orientation of the alkene is perpendicular to the M-C bond are significantly higher in energy See:
  • 59
    • 2342460950 scopus 로고    scopus 로고
    • The X-ray crystal structure of a known Pd(Ar)(NArR′) complex supports the illustrated trigonal planar geometry of the sp2-hybridized nitrogen atom. See:
    • The X-ray crystal structure of a known Pd(Ar)(NArR′) complex supports the illustrated trigonal planar geometry of the sp2-hybridized nitrogen atom. See:. Yamashita M., and Hartwig J.F. J. Am. Chem. Soc. 126 (2004) 5344-5345
    • (2004) J. Am. Chem. Soc. , vol.126 , pp. 5344-5345
    • Yamashita, M.1    Hartwig, J.F.2
  • 60
    • 67650222823 scopus 로고    scopus 로고
    • note
    • Examination of molecular models suggests that low diastereoselectivities would be obtained in reactions that afford cis-2,5-disubstituted pyrrolidines if alkene aminopalladation occurred with the nonbonding nitrogen electrons directed towards the alkene π-system.
  • 61
    • 67650213538 scopus 로고    scopus 로고
    • note
    • An alternative explanation for formation of the cis-2,3-disubstituted piperazine 41 as the major stereoisomer, with low selectivity, would involve cyclization through a chair-like transition state in which the alkene was oriented in a pseudoaxial position (75). However, the alkene pi-system is perpendicular to the Pd-N bond in 75, which is anticipated to lead to high transition state energy. As such, we currently favor the boat-like transition state model for these transformations. For discussion of related transition states in alkene carbopalladation processes, see Ref. 22.{A figure is presented}


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.