메뉴 건너뛰기




Volumn 16, Issue 21, 2010, Pages 6317-6325

Stereodivergent quaternization of 2-alkyl-2-p-tolylsulfinylacetonitriles: NMR spectroscopic evidence of planar and pyramidal benzylic carbanions

Author keywords

Asymmetric synthesis; Carbanions; Chirality; Diastereo selectivity; NMR spectroscopy

Indexed keywords

18-CROWN-6; ALKYL HALIDES; ASYMMETRIC SYNTHESIS; BENZYLIC; COUNTERIONS; DIASTEREO-SELECTIVITY; DIASTEREOISOMERS; ELECTROPHILES; ENANTIOMERIC PURITY; EXPERIMENTAL CONDITIONS; HEXAMETHYLDISILAZANE; NMR SPECTROSCOPY; PYRAMIDAL STRUCTURES; QUATERNIZATION; SPECTROSCOPIC EVIDENCE; SPECTROSCOPIC STUDIES; STEREO-SELECTIVE;

EID: 77952705499     PISSN: 09476539     EISSN: 15213765     Source Type: Journal    
DOI: 10.1002/chem.200903521     Document Type: Article
Times cited : (21)

References (53)
  • 16
    • 77952707447 scopus 로고    scopus 로고
    • Wiley-VCH, Weinheim, Charter 4
    • Z. Ludwig, Antifungal Azoles, Wiley-VCH, Weinheim, Charter 4, pp. 111-144.
    • Antifungal Azoles , pp. 111-144
    • Ludwig, Z.1
  • 43
    • 77952689058 scopus 로고    scopus 로고
    • note
    • The notation used for the alkylation products throughout the text consists of one number and two letters. The number indicates the reaction that is taking place: 7 for benzylation, 8 for methylation, 9 for ethylation, and 10 for allylation. The lower-case letter refers the nature of the alkyl group present in the starting compound, as depicted in Scheme 1. Finally, the capital letter, A or B, indicates the configuration at the benzylic center. When compounds 3 are drawn as indicated in the figure, with the C-CN bond parallel to the C-SOTol bond, isomers A and B are generated by approach of the alkylating reagents to the upper and bottom faces of the molecule, respectively. In those cases in which the priority order of the R′ group (reagent) is lower than that of the R group (substrate), according to Cahn-Ingold-Prelog rules, A isomers exhibit identical configuration at both benzylic carbon and sulfinyl group (S in the cases herein presented), whereas this is true for those B isomers when the priority order of R and R′ changes. (Chemical Equation Presented)
  • 47
    • 77952730882 scopus 로고    scopus 로고
    • note
    • 2.
  • 48
    • 77952693047 scopus 로고    scopus 로고
    • This structure has also been suggested for some lithium 2-p-tolylsulfinyl benzyl carbanions on the basis of theoretical calculations (see ref. [10])
    • This structure has also been suggested for some lithium 2-p-tolylsulfinyl benzyl carbanions on the basis of theoretical calculations (see ref. [10]).
  • 49
    • 77952736525 scopus 로고    scopus 로고
    • Structures similar to 3a-I′ have been suggested for other benzylic carbanions stabilized by cyano groups and generated in the presence of [1.8]crown-6 ether (see ref. [11] and references therein)
    • Structures similar to 3a-I′ have been suggested for other benzylic carbanions stabilized by cyano groups and generated in the presence of [1.8]crown-6 ether (see ref. [11] and references therein).
  • 50
    • 77952722529 scopus 로고    scopus 로고
    • Reactions were considerably slower in toluene than in THF and the formation of alkyl (Et, Pr, or Bn) 2-p-tolylsulfinylphenyl ketones (14-16) was detected
    • Reactions were considerably slower in toluene than in THF and the formation of alkyl (Et, Pr, or Bn) 2-p-tolylsulfinylphenyl ketones (14-16) was detected.
  • 51
    • 77952695936 scopus 로고    scopus 로고
    • This effect is quite analogous to the well-known influence reported for an axial methyl group on C3 and C5 positions of a cyclohexane ring
    • This effect is quite analogous to the well-known influence reported for an axial methyl group on C3 and C5 positions of a cyclohexane ring.
  • 52
    • 84855635765 scopus 로고    scopus 로고
    • 2) states precludes the presence of a unique geometry
    • 2) states precludes the presence of a unique geometry


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.