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31.
Reactions of 1-alkynyl-1-chlorocyclopropanes with lithium dialkylamides gave previously unknown 1-alkynyl-2-dialkylaminocyclopropanes.
1-(Alk-1-ynyl)-2-diazolylcyclopropanes were obtained by reactions of 1-alkynyl-1-chlorocyclopropanes with diazoles in the
presence of KOH in DMSO at 100 °C. These reactions passed through the formation of conjugated alky-nylcyclopropenes and reversible
addition of amide anions to them. The regioselectivity and stereoselectivity of these transformations depend on the substituents
in the starting chlorocyclopropanes and amines. 相似文献
32.
Conclusions Previously unreported 3-cyclopropyl-2-propyn-1-ol and cyclopropylpropionaldehyde were synthesized. This aldehyde yielded the first reported acetylenic fulvene, namely 6-(cyclopropylethynyl)fulvene, which is rather stable in solution in the cold.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2146–2147, September, 1985. 相似文献
33.
Misochko EY Akimov AV Korchagin DV Masitov AA Shavrin KN 《Physical chemistry chemical physics : PCCP》2012,14(6):2032-2039
The ESR spectrum of 5-methylhexa-1,2,4-triene-1,3-diyl (1) was recorded in an argon matrix at 15 K. The derived zero-field splitting (ZFS) parameters (D = 0.5054 ± 0.0006 cm(-1) and E = 0.0045 ± 0.0002 cm(-1)) fall between those determined previously for propargylene (2) and vinylcarbene (3). DFT and ab initio (CAS and MRCI) quantum-chemical calculations of the ZFS parameters of 1, 2, and 3 were performed. These calculations indicate that multireference methods are needed to successfully predict ZFS parameters of delocalized carbenes/biradicals such as 1-3. The calculated singly occupied MOs and spin density distributions show that the spin is more delocalized in 1 than in 2 and 3, indicating that 1 is a "hybrid" of the constituent ethynyl- and vinylcarbenes, 2 and 3, respectively. The dominant contribution to the D-value in 1 and 2 is found to result from spin-spin interactions on the C atoms of the propylidene moiety, which is strongly affected by spin polarization. Accurate values for the D-parameter are also predicted for other types of delocalized triplet carbenes such as HC(5)H and HCCN. 相似文献
34.
35.
K. N. Shavrin I. V. Krylova I. E. Dolgii O. M. Nefedov 《Russian Chemical Bulletin》1992,41(5):885-891
1,1-Dichloro-2-alkynes R1CCCHCl2 (4a–g; R1=Me, n-Pr, c-Pr, t-Bu, Ad, Nor, Ph) were synthesized with yields of 50–75% by chlorination with PCl5 of formylacetylenes (3a–g), prepared by oxidation of propargyl alcohols (1a–d) with CrO3·Py·HCl complex or acidolysis of propargyl acetals (2a–c) in the presence of catalytic quantities of pyridine; the corresponding alkynylchlorocarbenes, R1CCCCl (5a–g) were generated from them with powdered KOH in a two-phase system or t-BuOK. The latter were trapped by olefins with formation of 1-chloro-1-alkynylcyclopropanes (6a–t) with yields of up to 90%.See [1] for Communication 1.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1128–1135, May, 1992. 相似文献
36.
Chlorination of propargyl aldehyde with PCl5 in CH2Cl2 at –20 °C in the presence of catalytic amounts of pyridine afforded dichloromethylacetylene. Reaction of the latter with powdered KOH under phase-transfer catalysis conditions gave chlorovinylidenecarbene due to -elimination of HCl. In the presence of alkenes the carbene undergoes addition at the double bond giving chlorovinylidenecyclopropanes in 20–45 % yields.For the previous communication, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1242–1244, July, 1993. 相似文献
37.
The treatment of Z-1,1,3-trichloro-4,4-dimethyl-2-pentene (Ia) with t-C4H9OK in boiling hexane or benzene gave rise to (Z-2-chloro-3,3-dimethyl-1-butenyl)chlorocarbene (IVa), which reacted with alkenes to give the cyclopropane derivatives (V) in 44–57% yields. Dichloro-(2-chloro-1-alkenyl)methanes (Ib-d), which have a hydrogen atom at the C3 position of the alkenyl substituent, were also used as carbene precursors under these conditions. These compounds gave rise to mixtures of the cyclopropanes (VI)–(VIII) (obtained in up to 57% yields) and the dienes (IX)–(XI) (yields up to 54%). The reaction of cis-2-butene with (2-chloro-1-cyclopentenyl)chlorocarbene (IVd) was found to be completely stereospecific, indicating that this carbene exists in a singlet ground state.For previous communication, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2552–2558, November, 1991. 相似文献
38.
Gvozdev V. D. Shavrin K. N. Baskir E. G. Egorov M. P. Nefedov O. M. 《Russian Chemical Bulletin》2016,65(7):1829-1838
Russian Chemical Bulletin - A one-pot synthesis of arylmethylidene-substituted 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazoles based on the reaction of alk-4-ynals with 1,2-diaminobenzenes in DMSO at... 相似文献
39.
Russian Chemical Bulletin - 相似文献