Theoretical study of the substituent effect of hydroxy group on tandem Cope rearrangement and [2 + 2] cycloaddition in cis-1,2-diethynylcyclopropane and its mono-hetero analogues
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The tandem Cope rearrangement and [2 + 2] cycloaddition of cis-1,2-diethynyl-1,2-dihydroxycyclopropane and its mono-hetero analogues have been investigated at the B3LYP/6-31+G* level. The presence of the hydroxy group lowers the activation enthalpies for the Cope rearrangement, whereas activation enthalpies for the [2 + 2] cycloaddition are raised as compared to those for their non-hydroxy derivatives. The NBO analysis indicates that in the transition structure involved in the Cope rearrangement, lone pairs of the oxygen atoms of the hydroxy groups are transferred into the σ* C–C bond undergoing migration, as a result of which it is weakened. On the other hand, the lone pairs of the oxygen atoms interact with the π* C=C orbitals of the bis-allenic systems in the intermediate thereby stabilizing it and, thus, suppressing its driving ability for the [2 + 2] cycloaddition. In the products so formed, 6π electrons are delocalized conferring stability on them, which is further augmented by extended conjugation with the hydroxy groups. Due to high stability of these products, activation barrier for the change of enol into ketone is very high.
Keywordscis-1,2-Diethynyl-1,2-dihydroxycyclopropane Cope rearrangement [2 + 2] Cycloaddition Effect of hydroxy group DFT studies
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- 3.Hill RK (1991) Cope, oxy-Cope and anionic oxy-Cope rearrangements in comprehensive organic synthesis, vol 5. Pergamon Press, Oxford, pp 785–826Google Scholar
- 5.Durairaj K (1994). Curr Sci 66:917Google Scholar
- 6.Hikami K, Nakai T (1982) Chem Lett 1350Google Scholar
- 10.Wilson JW, Sherrod SA (1968) Chem Commun (London) 1443Google Scholar
- 12.MacMillan JH, Viola A Adapted from https://archive.org/details/TheAcetylenic-oxy-copeRearrangementOf15-hexadiyne-3-olAndMethyl. Accessed 20 Oct 2018
- 14.D’Amore MB, Bergman RG, Kent ME, Hedaya E (1972) J Chem Soc Chem Commun 49Google Scholar
- 17.Frisch MJ, Trucks GW, Schlegel HB, Scuseria GE, Robb MA, Cheeseman JR, Montgomery JA, Vreven Jr T, Kudin KN, Burant JC, Millam JM, Iyengar SS, Tomasi J, Barone V, Mennucci B, Cossi M, Scalmani G, Rega N, Petersson GA, Nakatsuji H, Hada M, Ehara M, Toyota K, Fukuda R, Hasegawa J, Ishida M, Nakajima T, Honda Y, Kitao O, Nakai H, Klene V, Li X, Knox JE, Hratchian HP, Cross JB, Bakken V, Adamo C, Jaramillo J, Gomperts V, Stratmann RE, Yazyev O, Austin AJ, Cammi R, Pomelli C, Ochterski JW, Ayala PY, Morokuma K, Voth GA, Salvador P, Dannenberg JJ, Zakrzewski VG, Dapprich S, Daniels AD, Strain MC, Farkas O, Malick DK, Rabuck AD, Raghavachari K, Foresman JB, Ortiz JV, Cui Q, Baboul AG, Clifford V, Cioslowski J, Stefanov BB, Liu G, Liashenko A, Piskorz P, Komaromi I, Martin RL, Fox DJ, Keith T, Al-Laham MA, Peng CY, Nanayakkara A, Challacombe M, Gill PMW, Johnson B, Chen W, Wong MW, Gonzalez C, Pople JA (2003) Gaussian 03, Revision B.05. Gaussian, Inc., WallingfordGoogle Scholar
- 21.Foresman JB, Frisch AE (2015) Exploring chemistry with electronic structure methods3rd edn. Gaussian Inc, Wallingford, p 380Google Scholar