메뉴 건너뛰기




Volumn 2, Issue 6, 2010, Pages 621-623

Chemoselectivity in asymmetric aminocatalysis

Author keywords

Aldehydes; Cascade reaction; Chemoselectivity; Organocatalysis; Water solubility

Indexed keywords


EID: 78651492461     PISSN: 18673880     EISSN: 18673899     Source Type: Journal    
DOI: 10.1002/cctc.201000110     Document Type: Article
Times cited : (27)

References (30)
  • 1
    • 66449129817 scopus 로고    scopus 로고
    • IUPAC definition. For an inspiring conspectus on the topic, see
    • IUPAC definition. For an inspiring conspectus on the topic, see: R. A. Shenvi, D. P. O'Malley, P. S. Baran, Acc. Chem. Res. 2009, 42, 530-541.
    • (2009) Acc. Chem. Res. , vol.42 , pp. 530-541
    • Shenvi, R.A.1    O'Malley, D.P.2    Baran, P.S.3
  • 3
    • 79957737068 scopus 로고    scopus 로고
    • For recent reviews.
    • For recent reviews.
  • 4
    • 77951531050 scopus 로고    scopus 로고
    • B. List, Angew. Chem. 2010, 122, 1774-1779
    • (2010) Angew. Chem. , vol.122 , pp. 1774-1779
    • List, B.1
  • 16
    • 4544236616 scopus 로고    scopus 로고
    • The fact that the aldehydic products 5 resist further aldol reaction under proline catalysis provides another example of chemoselectivity. This crucial observation set the stage for a two-step de novo synthesis of carbohydrates
    • The fact that the aldehydic products 5 resist further aldol reaction under proline catalysis provides another example of chemoselectivity. This crucial observation set the stage for a two-step de novo synthesis of carbohydrates: A. B. Northrup, D. W. C. Mac Millan, Science 2004, 305, 1752-1755.
    • (2004) Science , vol.305 , pp. 1752-1755
    • Northrup, A.B.1    MacMillan, D.W.C.2
  • 17
    • 70450189000 scopus 로고    scopus 로고
    • For a recent example of chemoselective cross-aldol reaction controlled by electronic factors using a primary amine as organocatalyst, see
    • For a recent example of chemoselective cross-aldol reaction controlled by electronic factors using a primary amine as organocatalyst, see: M. Markert, U. Scheffletr, R. Mahrwald, J. Am. Chem. Soc. 2009, 131, 16642-16643.
    • (2009) J. Am. Chem. Soc. , vol.131 , pp. 16642-16643
    • Markert, M.1    Scheffletr, U.2    Mahrwald, R.3
  • 22
    • 30844471959 scopus 로고    scopus 로고
    • In water/octanol (1:1) systems n-butanal partitions into the aqueous phase approximately 1000 times more favorably than n-decanal (logD 0.88 vs 4.008), see
    • In water/octanol (1:1) systems n-butanal partitions into the aqueous phase approximately 1000 times more favorably than n-decanal (log D 0.88 vs 4.008), see: R. Benigni, L. Conti, R. Crebelli, A. Rodomonte, M. R. Vari, Environ. Mol. Mutagen. 2005, 46, 268-280.
    • (2005) Environ. Mol. Mutagen. , vol.46 , pp. 268-280
    • Benigni, R.1    Conti, L.2    Crebelli, R.3    Rodomonte, A.4    Vari, M.R.5
  • 23
    • 79957731492 scopus 로고    scopus 로고
    • For the first report on the conjugated addition of aldehydes to nitroalkenes catalyzed by O-protected prolinol B, see.
    • For the first report on the conjugated addition of aldehydes to nitroalkenes catalyzed by O-protected prolinol B, see.
  • 28
    • 33751571805 scopus 로고    scopus 로고
    • The conjugate additions catalyzed by B in the presence of water generally take place in the concentrated substrate phase, see, The 'perfectly suited' role of catalyst B in selectively promoting the conjugate addition synergistically combines with the inertness toward the homo-aldol reaction of aldehydes. This behavior may explain the absence of byproducts such as 12 that would consume the more hydrophobic aldehydic component 6.
    • The conjugate additions catalyzed by B in the presence of water generally take place in the concentrated substrate phase, see: A. Carlone, M. Marigo, C. North, A. Landa, K. A. Jørgensen, Chem. Commun. 2006, 4928-4930. The 'perfectly suited' role of catalyst B in selectively promoting the conjugate addition synergistically combines with the inertness toward the homo-aldol reaction of aldehydes. This behavior may explain the absence of byproducts such as 12 that would consume the more hydrophobic aldehydic component 6.
    • (2006) Chem. Commun. , pp. 4928-4930
    • Carlone, A.1    Marigo, M.2    North, C.3    Landa, A.4    Jørgensen, K.A.5
  • 29
    • 79957770879 scopus 로고    scopus 로고
    • Decreasing the pH of the buffer from 8.0 to 7.0 resulted in greater selectivity for the desired "cross" cascade product over the undesired "homo" products, but other side reactions, such as aldol-type reactions of the aldehydes and the conjugate addition of nitromethane to the nitroalkene intermediate, increased. As the buffer pH dropped below 7.0, the rate, selectivity, and yield of the reaction decreased along with pH. Below a pH of approximately 6.5 (near the isoelectric point of proline), the first step of the reaction was strongly inhibited.
    • Decreasing the p H of the buffer from 8.0 to 7.0 resulted in greater selectivity for the desired "cross" cascade product over the undesired "homo" products, but other side reactions, such as aldol-type reactions of the aldehydes and the conjugate addition of nitromethane to the nitroalkene intermediate, increased. As the buffer p H dropped below 7.0, the rate, selectivity, and yield of the reaction decreased along with p H. Below a p H of approximately 6.5 (near the isoelectric point of proline), the first step of the reaction was strongly inhibited.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.