Alkynylhalocarbenes

Directed nucleophilic addition of phenoxides to cyclopropenes

“…4 Related transformations of highly strained symmetric spirocyclic polycyclopropanes are also known. 5 However, the reactions of substituted cyclopropenes are typically not diastereoselective, 6 unless the selectivity is enforced by excessive steric hindrance. 7 We have previously reported a formal nucleophilic substitution of bromocyclopropanes operating via dehydrohalogenation/addition of O -based nucleophiles to cyclopropene intermediates, which can be carried out in both inter- 8 or intramolecular fashion.…”

Synthesis of 5-methylidenehexahydropyrrolo[l,2-a]imidazoles and 6-methylideneoctahydropyrrolo[l,2-a]pyrimidines by the reaction of 1-alkynyl-1-chlorocyclopropanes with lithium derivatives of 1,2- and 1,3-diaminoalkanes

“…3 Proceeding from the available data published earli er 3,12-14 and the data obtained in this work, the formation of products 3, 4, and 7 can be described as follows (Scheme 4). Competition of the primary and secondary amino groups results in the formation of a mixture of the corresponding E isomer of N methyl substituted pyrimidine 7 and trans isomer of aminocyclo propane 8 in the ratio 1.5 : 1 in 68% total yield (Scheme 3).…”

Reactions of 1-(alk-1-ynyl)-1-chlorocyclopropanes with arenethiols and alkanethiols in dimethyl sulfoxide in the presense of KOH

“…Cyclo propene 2b was synthesized by the action of lithium diethylamide on chlorocyclopropane 1b according to the procedure published earlier. 8 The product obtained (87 mg, ~85% purity) was added to a mixture of DMSO (2 mL), BuSH (450 mg, 5 mmol), and КОН (112 mg, 2 mmol) preheated to 100 °С, and the reaction mixture was stirred for 15 min. After completion of the reaction, water (5 mL) and ether (10 mL) were added, the organic layer was separated, the aqueous layer was extracted with ether three times.…”

“…The possibility of pro ceeding of related processes was described in literature. 12, 13 The experimental confirmation of this assumption is the fact that compound 4а was obtained in 30% yield without admixture of the acetylenic isomer 3e upon heating of cyclopropane 1b with a fivefold excess of sodium butane thiolate (obtained previously from butanethiol and sodium hydride) in DMSO at 100 °С for 16 h. On the contrary, trans cyclopropane 3e was obtained in 45% yield upon reaction of cyclopropene 2b prepared as described previ ously, 8 with butanethiol in DMSO in the presence of KOH at 100 °С. Hence, product 4а was obtained directly from chloride 1b.…”

“…3 They are also used in the synthesis of nitrogen containing heterocycles, 5 conjugated alkynyl and iminoalkylcyclopropenes. 6, 7 Recently, 8 we have found that reactions of 1 alkynyl 1 chlorocyclopropanes with alcohols and phenols in DMSO in the presence of КОН is a convenient approach to 1 alkynyl 2 alkoxy and 1 alkynyl 2 phenoxycyclo propanes, which had widely been applied previously in the synthesis of various carbocyclic compounds. [9][10][11] In continuation of these works, it was of interest to study the addition of thiols to these substrates.…”