Remote protection prevents unwanted cyclizations with 2-aminopyridines

Tetrahedron Letters

Volumn 47, Issue 34, 2006, Pages 6113-6115

  Lawton, Graham R ^a   Ji, Haitao ^a   Silverman, Richard B ^a  

^a NORTHWESTERN UNIVERSITY   (United States)

Author keywords

2 Aminopyridines; Mitsunobu reaction; Prevent cyclization; Remote protection; Side reaction

Indexed keywords

2 AMINOPYRIDINE; AMINO ACID DERIVATIVE; NITROGEN DERIVATIVE;

ARTICLE; CHEMICAL REACTION KINETICS; CYCLIZATION; MITSUNOBU REACTION; REACTION ANALYSIS; SUBSTITUTION REACTION;

EID: 33746023969     PISSN: 00404039     EISSN: None     Source Type: Journal    
DOI: 10.1016/j.tetlet.2006.06.091     Document Type: Article

References (13)

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4. For an example of a similar reaction see:. Yasuda N., Hsaiao Y., Jensen M.S., Rivera N.R., Yang C., Wells K.M., Yau J., Palucki M., Tan L., Dormer P.G., Volante R.P., Hughes D.L., and Reider P.J. J. Org. Chem. 69 (2004) 1959-1966
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6. 4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel, eluting with hexanes/ethyl acetate 8:2. In the case of 1a and 1c different reaction conditions, order of addition, reagent concentrations and temperatures failed to have any significant effect on product yield. Compound 3 was eluted with ethyl acetate/methanol 9:1.
7. +). Compound 4b was also analyzed by COSY and NOESY. A strong NOE was seen between the protons at the 3 and 4 positions of the pyrrolidine ring, indicating that the stereochemistry is indeed cis. Only one diastereomer is produced in the formation of 4b, indicating that the Mitsunobu reaction proceeded with complete inversion of stereochemistry.
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