2-Ethoxyvinyllithiums and diethoxyvinyllithiums : what makes them stable or fragile?
作者:Manfred Schlosser、Heng-xu Wei
DOI:10.1016/s0040-4020(96)01075-7
日期:1997.2
The elusive (E)-2-ethoxyvinyllithium can be readily generated in tetrahydrofuran at -75 degrees C from (E)-1-bromo-2-ethoxyethylene by halogen/metal exchange and subsequently trapped with electrophiles. Alkylation opens a convenient entry to (E)-configurated enethers. (E)-2-Ethoxyvinyllithium decomposes rapidly at -50 degrees C whereas its (Z)-isomer, which lacks the possibility to eliminate lithium ethoxide in a favorable anti-periplanar process, is stable under the same conditions. (E)-1,2-Diethoxyvinyllithium even sustains reflux temperatures (approximately 75 degrees C). 2,2-Diethoxyvinyllithium and (Z)-1,2-diethoxyvinyllithium can be conserved at 0 degrees C although this time loss of alcoholate can occur in the anti-mode. Obviously it matters whether the energy-rich ethoxyacetylene is formed as the elimination product or simple acetylene, as in the case of (E)-2-ethoxyvinyllithium. (C) 1997, Elsevier Science Ltd.
Ponomarev, S. V.; Nikolaeva, S. N.; Molchanova, G. N., Journal of general chemistry of the USSR, 1984, vol. 54, p. 1620 - 1623
作者:Ponomarev, S. V.、Nikolaeva, S. N.、Molchanova, G. N.、Kostyuk, A. S.、Grishin, Yu. K.
DOI:——
日期:——
The synthesis of trialkyl silyl alkoxyacetylenes and ?-bromo-?-trialkyl silyl vinyl ethers
作者:L. L. Shchukovskaya、R. I. Pal'chik
DOI:10.1007/bf00844237
日期:1964.12
Shchukovskaya,L.L. et al., Journal of general chemistry of the USSR, 1973, vol. 43, p. 1974 - 1976
作者:Shchukovskaya,L.L. et al.
DOI:——
日期:——
Zaitseva, G. S.; Novikova, O. P.; Livantsova, L. I., Journal of general chemistry of the USSR, 1991, vol. 61, # 6.2, p. 1268 - 1273
作者:Zaitseva, G. S.、Novikova, O. P.、Livantsova, L. I.、Petrosyan, V. S.、Baukov, Yu. I.