Cyclopropane Cyclopropylamine

Cyclopropanemethanol Cyclopropanone Cyclopropane Cyclopropylamine Cyclopropylbenzene Cyclopropyl methyl ether Cyclopropyl methyl ketone... 

Cyclophanes, 24 37-38 Cyclopropanes, 13 654 26 654 Cyclopropenyl acids, 5 28 Cyclopropylamine (CPA) in nevirapine synthesis, 15 741-742 physical properties of, 2 498t Cyclopropyl bromide, physical properties of, 4 350t... 

We have examined the above-described series of trans- and c/s-2-fluoro-2-phenylcyclopropylamine analogues (60a-d, 61a-d) as inhibitors of recombinant human liver MAO A and B [134]. The presence of fluorine attached to a cyclopropane ring, especially for frans-isomer 8a, was found to result in an increase in inhibitory activity toward both MAO A and B (Table 4). In addition, p-substitution of electron-withdrawing groups, such as Cl and F, in the aromatic ring of the frans-isomers (60b-d) increased the inhibition of both enzymes. On the other hand, the introduction of fluorine at 2-position of c/s-isomer 8b resulted in loss of inhibitory activity for both MAO A and B, and no further p-aromatic substitution for c/s-isomer greatly affected on the inhibitory activity with either enzymes. In addition, both MAO A and B were selectively inhibited by the (1S,2S)-enantiomer of 60a, while no inhibition was observed with the (1f ,2f )-enantiomer [134]. As already described in the former section, several questions on the mechanistic pathway for MAO inhibition by cyclopropylamines still remain. However,... 

A very useful class of chiral auxiliaries has been developed for alkenes substituted with a heteroatom. These auxiliaries, attached to the heteroatom, allow for the preparation of enantiomerically enriched cyclopropanols, cyclopropylamines and cyclopropylboronic acids. Tai and coworkers have developed a method to efficiently generate substituted cyclopropanol derivatives using the cyclopropanation of a chiral enol ether (equation 78) . The reaction proceeds with very high diastereocontrol with five- to eight-membered ring sizes as well as with acyclic enol ethers. The potential problem with the latter is the control of the double bond geometry upon enol ether formation. A detailed mechanistic study involving two zinc centers in the transition structure has been reported. ... 

The cyclopropanation of a chiral enamide has been investigated for the preparation of fluoro-substituted cyclopropylamines. Unfortunately, the reaction produced a mixture of all four possible stereoisomers when the chiral starting material was submitted to the a-fluoro iodomethylzinc carbene (equation 80). ... 

The next section makes use of the much more recent observation19 that there is a nearly constant difference of the enthalpies of formation of corresponding vinyl and phenyl derivatives. If vinyl relates to cyclopropyl, and vinyl also relates to phenyl, then how do corresponding cyclopropyl and phenyl derivatives relate Conceptually, vinylcyclopropane (10), also identified as 1, X = Cypr and 2, X = Vi) and styrene (11, X = Vi, also identified as 1, X = Ph) are thus relatable. Likewise, relatable are cyclopropylamine (2, X = NH2) and aniline (11, X = NH2)18. This thermochemical comparison of benzene and cyclopropane derivatives is not merely a check of two purported identities in terms of a third, arithmetically derivable, identity. Benzene is the archetypical 7i-delocalized aromatic species from which understanding of this widespread phenomenon evolves. Cyclopropane is the paradigm of cr-aromatic species from which understanding of this more exotic phenomenon evolves20. Benzene and cyclopropane are thus naturally paired as conceptual models for delocalization and aromaticity. Section III discusses these and related issues. 

It is well-recognized that the hydrocarbons cyclopropane and cyclobutane have nearly identical strain energies, and so these microcycles have been quite naturally paired in numerous treatments of molecular strain. How similar are cyclobutylamine (12, X = NH2, 13, n = 4, X = NH2) and cyclopropylamine (2, X = NH2,13, n - 3, X = NH2) and other correspondingly monosubstituted cyclobutanes and cyclopropanes18 What about... 

Cyclopentylmethyl methanesulfonate, 2862b Cyclopropanecarbonitrile, see Cyanocyclopropane, 1459 f Cyclopropane, 1193 f Cyclopropylamine, 1252 f Cyclopropyl methyl ketone, 1901... 

Cyanopyridines undergo titanium-mediated reductive cyclopropanation to give pyridylcyclopropylamines in good yield <20030L753>. Both 2- and 3-cyanopyridine react with the titanium species 81 formed from diethylzinc and methyltriisopropyloxytitanium in the presence of lithium isopropoxide to give the cyclopropylamine product in 80% and 82% yield, respectively (Equation 55). 

Cyclopropane carboxylic acid chloride cyprofuram, profluralin, trinexapac Cyclopropylamine cyprazine, cyromazine, procyazine Cyclopropyl p.chloro phenyl ketone flucycloxuron... 

In addition, other carboxylic acid derivatives, such as tertiary carboxamides and cyclic carbonates, readily undergo cyclopropanation reactions under similar conditions to provide cyclopropylamines ° and cyclopropanone hemiacetals," respectively. The cognate titanium-mediated coupling of imides has been shown to afford synthetically useful N-acylhemiaminals. ... 

Small variations in Jch were found in monosubstituted cyclopropanes, such that in cyclopropylamine (87), Jc(1)h = 173 Hz and Jc(2)h =161 Hz . Subsequently Crecely... 

Cyclopropylamine (77) could be oxidized to nitrosocyclopropane (432) by oxygen difluoride or m-chloroperbenzoic acid (equation 106). Azo compounds 433 and 435 were obtained by oxidation of 434 by IF5 (equation 107) or condensation of 77 with a nitroso compound (equation 106). Interconversions of an aminocyclopropane into an isocyano or azido cyclopropane are described, for example, in Refs 105,479-481,515,516 and Refs 89, 461, 517, respectively. For formation of an N-cyclopropyl iminiophos-phorane see Ref. 518. Nitrosation of iV-cyclopropylurea derivatives was usually performed... 

Opening of the vicinal carbon-carbon bond in aminocyclopropane derivatives was achieved by oxidation with various reagents, e.g. Pb(OAc)4 , NaOCP r-BuOCpi Cu2 /0 Cu/0 0s04/0 K3Fe(CN) Cu or fiv/Oa/sens., anodic oxidation Oxidation with halogenating reagents such as NaOCl or t-BuOCl proceeds via N-chloro compounds (see equation 105), which opened the C(l)-C(2) cyclopropane bond when the cyclopropylamine had one substituent at the iV-atom (e.g. 489- 490 equation 125) or a phenyl moiety in the C(2) position. 

Cao, B., Xiao, D., Joullie, M. M. Synthesis of Bicyclic Cyclopropylamines by Intramolecular Cyclopropanation of N-Allylamino Acid Dimethylamides. Org. Lett. 1999, 1, 1799-1801. 

The Kulinkovich cyclopropanation, in which an ester and two equivalents of a Grignard reagent are combined to make a cyclopropanol in the presence of a catalytic amount of Cp2TiCl2, is a useful variant of reductive coupling reactions. A cyclopropylamine can be obtained instead if a tertiary amide is substituted for the ester. 

Cyclopropane derivatives. The intramolecular Kulinkovich reaction of 2-substituted 5-hexenoyl bomanesultams is a useful method for the synthesis of chiral endo-2-substituted bicyclo[3.1.0]hexan-l-ols. Extension of the reaction scope to amides results in the formation of cyclopropylamines and cyclopropylstannanes. ... 

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