139185-74-3Relevant academic research and scientific papers
ALKYNYLHALOCARBENES. 2. GENERATION OF (ALKYN-1-YL)CHLOROCARBENES BY BASIC SOLVOLYSIS OF 1,1-DICHLORO-2-ALKYNES AND THEIR REACTION WITH OLEFINS: SYNTHESIS OF 1-CHLORO-1-ALKYNYLCYCLOPROPANES
Shavrin, K. N.,Krylova, I. V.,Dolgii, I. E.,Nefedov, O. M.
, p. 885 - 891 (2007/10/02)
1,1-Dichloro-2-alkynes R1CCCHCl2 (4a-g: R1=Me, n-Pr, c-Pr, t-Bu, Ad, Nor, Ph) were synthesized with yields of 50-75percent 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 90percent.Keywords: alkynylchlorocarbenes, 1,1-dichloro-2-alkynes, basic solvolysis, interphase catalysis, 1-chloro-1-alkynylcyclopropanes.
Alkynylhalocarbenes: Generation from 1,1-Dihaloalk-2-ynes by Base Solvolysis and Reaction with Alkenes
Shavrin, Konstantin N.,Krylova, Irina V.,Shvedova, Inna B.,Okonnishnikova, Galina P.,Dolgy, Igor E.,Nefedov, Oleg M.
, p. 1875 - 1882 (2007/10/02)
A series of 1,1-dihaloalk-2-ynes 1-3 has been prepared by halogenation of the formylacetylenes 8 with PCl5 or an equimolar mixture of PCl5 and Br2.A simple, general means of access to the alkynylhalocarbenes 5 has been developed via base-initiated α-elimination of 1,1-dihalo-2-ynes (1-3).The carbenes 5a-i have been trapped by alkenes, to form 1-alkynyl-1-halocyclopropanes (11) in up to 90percent yield.Under the same conditions compound 1g was converted into the butadiene 12.Experimental evidence for the electrophilicity and the singlet nature of carbenes 5 has been obtained.
