Mono- and Disubstituted N,N-Dialkylcyclopropylamines from Dialkylformamides via Ligand-Exchanged Titanium–Alkene Complexes Part 79 in the series “Cyclopropyl Building Blocks for Organic Synthesis”. For part 78 see: M. Gensini, I. Kozhushkov, S. Yufit, K. Howard, M. Es-Sayed, de Meijere, Eur. J. Org. Chem. 2002, 2499–2507; part 77: H. Nüske, S. Bräse, I. Kozhushkov, M. Noltemeyer, M. Es-Sayed, de Meijere, Chem. Eur. J. 2002, 8, 2350–2369.

Meijere, Armin de; Williams, Craig M.; Kourdioukov, Alexandre I.; Sviridov, Sergei V.; Chaplinski, Vladimir; Kordes, Markus; Savchenko, Andrei I.; Stratmann, Christian; Noltemeyer, Mathias

doi:10.1002/1521-3765(20020816)8:16<3789::aid-chem3789>3.0.co;2-r

Cited by 96 publications

(108 citation statements)

References 17 publications

(21 reference statements)

Supporting

Mentioning

103

Contrasting

Unclassified

Order By: Relevance

“…15 Bromine-lithium exchange on cis/trans-7 under conditions as previously published for 1-bromobicyclopropyl, 16 The most straightforward approach to a dibenzyl-protected 2-cyclopropylcyclopropanamine would be by direct (dibenzylamino)cyclopropanation of ethenylcyclopropane (5) with dibenzylformamide in the presence of methyltitanium triisopropoxide and cyclohexylmagnesium bromide, as previously developed for a wide range of alkenes. 17 However, several attempts to perform this conversion were not met with success. This may be due to the fact that the essential intermediate, formed by ligand exchange on titanium with ethenylcyclopropane, has a cyclopropylcarbinyltitanium substructure and as such would be prone to undergo a rapid rearrangement of the type (cyclopropylcarbinyl)metal to (homoallyl)metal.…”

Section: Resultsmentioning

confidence: 99%

Convenient Synthesis of Ethenylcyclopropane and Some 2-Cyclopropylcyclopropane Derivatives¹

Rassadin¹,

Соколов²,

Khlebnikov³

et al. 2011

Synthesis

Self Cite

View full text Add to dashboard Cite

Ethenylcyclopropane (5) was prepared from cyclopropyl methyl ketone (1) in four simple, easily scalable steps (bromination, reduction to the bromohydrin, acetylation of the latter, and reductive elimination with Zn/Cu) in an overall yield of 56%. 1-Bromo-2-cyclopropylcyclopropane (7) (approximately 1:1 mixture of cis-and trans-7) was prepared from 5 via the dibromide 6, and from 7 the boronate cis/trans-8 (ratio 1:1) was obtained in 96% yield. Rhodium(II)-catalyzed cyclopropanation of 5 with ethyl diazoacetate gave ethyl 2-cyclopropylcyclopropanecarboxylate (cis/trans-9, ratio 1:1.4) in 80% yield. The latter was also prepared in 79% overall yield by sequential cyclopropanation of buta-1,3-diene with ethyl diazoacetate [under Rh 2 (OAc) 4 catalysis] and diiodomethane/diethylzinc/trifluoroacetic acid. Curtius degradation of 2-cyclopropylcyclopropanecarboxylic acid (obtained by hydrolysis of the ester) gave 2-cyclopropylcyclopropanamine (1:1.2 mixture of cis-and trans-isomers) in 58% yield.

show abstract

Section: Resultsmentioning

confidence: 99%

Convenient Synthesis of Ethenylcyclopropane and Some 2-Cyclopropylcyclopropane Derivatives¹

Rassadin¹,

Соколов²,

Khlebnikov³

et al. 2011

Synthesis

Self Cite

View full text Add to dashboard Cite

show abstract

“…The starting ethyl dispiro[2.0.2.1]heptane-7-carboxylate (9) [14] was obtained by rhodium-catalyzed addition of ethyl diazoacetate to bicyclopropylidene (19). [15] A much simpler approach to the diyne 6 would have been by direct addition of bis(trimethylsilylethynyl)methylene to bicyclopropylidene (19) (cf. refs.…”

Section: Resultsmentioning

confidence: 99%

Structural Parameters and Electronic Interactions in Substituted 1,1-Diethynylcyclopropanes − An Experimental Study

Meijere

Kozhushkov

Boese³

et al. 2002

Eur. J. Org. Chem.

Self Cite

View full text Add to dashboard Cite

Keywords: Alkynes / Conjugation / Diethynylcyclopropanes / Small ring systems / Structure elucidation 1,1-Bis(trimethylsilylethynyl)cyclopropane (4) and dimethyl 3,3Ј-(1,1-cyclopropanediyl)bis(2-propynoate) (5) have been prepared by silylation of the known 1-(bromoethynyl)-1-(trimethylsilylethynyl)cyclopropane (7) and by double carboxylation of 1,1-diethynylcyclopropane (3) followed by esterification, in 91 and 74% overall yields, respectively. 7,7-Diethynyldispiro[2.0.2.1]heptane (6) has been synthesized from ethyl dispiro[2.0.2.1]heptane-7-carboxylate (9) by a ten-step sequence in 41% overall yield. Upon UV irradiation, the diacetylene 4 underwent ethylene extrusion, and the resulting bis(trimethylsilylethynyl)carbene dimerized with electron reorganization to give 1,4,8-tris(trimethylsilyl)-3-(trimethylsilylethynyl)oct-3-ene-1,5,7-triyne (20) (24% yield). X-ray crystal structure analyses of 4, 5, and 6 revealed strong electronic

show abstract

“…6 The formylation of 5 with ethyl formate proceeded virtually quantitatively, and the dehydration of the N-formyl derivative 6 with phosgene furnished 7 in 65% yield (Scheme 2). Ethyl 1-isocyanocyclopropanecarboxylate (11) was prepared by cyclizing bisalkylation of ethyl isocyanoacetate (10).…”

Section: Synthesis Of New Cyclopropylisonitrilesmentioning

confidence: 99%

Synthesis of New Cyclopropylisonitriles and their Applications in Ugi Four-Component Reactions

Osipova¹,

Yufit²,

Meijere³

2007

Synthesis

Self Cite

View full text Add to dashboard Cite

show abstract

Cited by 96 publications

References 17 publications

Convenient Synthesis of Ethenylcyclopropane and Some 2-Cyclopropylcyclopropane Derivatives¹

Convenient Synthesis of Ethenylcyclopropane and Some 2-Cyclopropylcyclopropane Derivatives¹

Structural Parameters and Electronic Interactions in Substituted 1,1-Diethynylcyclopropanes − An Experimental Study

Synthesis of New Cyclopropylisonitriles and their Applications in Ugi Four-Component Reactions

Contact Info

Product

Resources

About