TY - JOUR
T1 - Dissecting alkynes
T2 - Full cleavage of polarized C≡C moiety via sequential bis-michael addition/retro-mannich cascade
AU - Roy, Saumya
AU - Davydova, Maria P.
AU - Pal, Runa
AU - Gilmore, Kerry
AU - Tolstikov, Genrikh A.
AU - Vasilevsky, Sergei F.
AU - Alabugin, Igor V.
PY - 2011/9/16
Y1 - 2011/9/16
N2 - The reaction of diaryl ketoalkynes with 1,2-diamino ethane leads to the full scission of the triple bond with the formation of acetophenone and imidazoline fragments. In this transformation, one of the alkyne carbons undergoes formal reduction with the formation of three C-H bonds, whereas the other carbon undergoes formal oxidation via the formation of three C-N bonds (one π and two σ). Computational analysis confirmed that the key fragmentation step proceeds via a six-membered TS in a concerted manner. Both amines are involved in the fragmentation: the N-H moiety of one amine transfers a proton to the developing negative charge at the enolate oxygen, while the other amine provides direct stereoelectronic assistance to the C-C bond cleavage via a hyperconjugative nN → σ*C-C interaction.
AB - The reaction of diaryl ketoalkynes with 1,2-diamino ethane leads to the full scission of the triple bond with the formation of acetophenone and imidazoline fragments. In this transformation, one of the alkyne carbons undergoes formal reduction with the formation of three C-H bonds, whereas the other carbon undergoes formal oxidation via the formation of three C-N bonds (one π and two σ). Computational analysis confirmed that the key fragmentation step proceeds via a six-membered TS in a concerted manner. Both amines are involved in the fragmentation: the N-H moiety of one amine transfers a proton to the developing negative charge at the enolate oxygen, while the other amine provides direct stereoelectronic assistance to the C-C bond cleavage via a hyperconjugative nN → σ*C-C interaction.
UR - http://www.scopus.com/inward/record.url?scp=80052757000&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80052757000&partnerID=8YFLogxK
U2 - 10.1021/jo201259j
DO - 10.1021/jo201259j
M3 - Article
AN - SCOPUS:80052757000
VL - 76
SP - 7482
EP - 7490
JO - Journal of Organic Chemistry
JF - Journal of Organic Chemistry
SN - 0022-3263
IS - 18
ER -