Amino cyclopropanation

Scheme 11.27. Straightforward transformation of the cyclopropanol 98 into amino-cyclopropane derivative 101 [123].

The mechanism of this unusual cis addition has not been clarified. The bromoethyl derivative 2 can be further alkylated (intramolecularly) to give the deuterated cyclopropyl derivative 3. Once again, cis addition predominates, with 46% de. Upon hydrolysis of the cyclopropyl derivative, optically active (V)-l-amino-cyclopropane-2-r/2-l-carboxylic acid (4) in 44% yield and 46% ee is obtained. 

Liirssen, K., Naumann, K. Schroder, R. (1979). 1-Amino-cyclopropane-l-carboxylic acid - an intermediate of ethylene biosynthesis in higher plants. Zeitschrift fur Pflanzenphysiologie 92, 285-94. 

Sato, T., Oeller, P.W. Theologis, A. (1991). The 1-amino-cyclopropane-l-carboxylate synthase of Cucurbita. Journal of Biological Chemistry 266, 3752-9. 

In contrast to the restricted occurrence of the secondary metabolites mentioned previously, all plants contain 1-amino-cyclopropane-l-carboxylic acid. This amino acid is the precursor of ethylene. In the course of the bios)mthesis of this gaseous phytohormone, 1-aminocyclopropane-l-carboxylic acid is oxidized and decomposed to yield ethylene, HCN, CO2 and water (John, 1997). 

SYNS PARNATE trans-2-PHENYL-l-AMINO-CYCLOPROPANE SKF 385 TRANILCYPROMINE ... 

An electron-deficient center attached to an amino cyclopropane derivative generally causes a ring enlargement. Reactions of this type are shown in equations 116-119. 

In a number of cases, ring-opened products are isolated together with or instead of the amino-cyclopropane. 

Fig. Id. Ethylene Exhylcnt 1-amino-cyclopropane-1-carboxylic acid (ACC).

ACC 1 -amino-cyclopropane- 1-carboxylic acid 2,4,5-T 2,4,5-trichlorophenoxyacetic acid... 

Enzymes may also catalyze transformations of a highly selective and nniqne natnre snch as in transformations of small molecnles. Examples are the fragmentation of 1-amino-cyclopropane-1-carboxylate to the frnit ripening hormone ethylene, the cycloreversion of thymine dimers in DNA repair, the synthesis of isopenicUhn and the rednction of molecn-lai nitrogen (N2) to ammonia... 

Neoefrapeptins, neoefrapeptin A Ac-Pip-Aib- Pip- Iva-Aib- Leu-/3 -Ala-Gly-Acc-Aib-Pip-Gly-Leu-Iva-aX, a group of peptides with insecticidal activity isolated from the fungus Geotrichum candidum. AU 12 neoefrapeptins (A-I, L-N) contain the very rare amino acid 1-amino-cyclopropane-carboxylic acid (Acc), and some of them (F, I, L, M) also contain (2S,3S)-3-methyl-proline instead of pipecolic acid (Pip) in position 11. Further unusual building blocks are isovaline (Iva) and the C-terminal amide moiety X = 2,3,4,6,7,8-hexahydro-l-pyrrolo [ 1,2-a]pyrimidine. Neoefrapeptins show a close sequence similarity to the efrapeptins [A. Fredenhagen et al., J. Antibiot. 2006, 59, 2006]. 

Because 1 mole of cyanide is produced for each mole of ethylene generated from ACC (1-amino-cyclopropane-1-carboxylic acid) see Chapter 13), all plants must contain small amounts of cyanide (Peiser et al., 1984). However, due to a concomitant increase in the amount of (3-cyanoalanine synthase, the ability to detoxify cyanide in the tissues is much higher (Manning, 1988). 

S-Adenosy I methionine, 0-,N-S- and C-methylated compounds, acetidine-2-carboxylic add, 1-amino-cycLopropane carboxylic acid, spermidine, thiamine... 

The biosynthesis begins from methionine (63 see Chapter 27) with 1-amino-cyclopropane-l-carboxylic acid (64, ACC see Chapter 28) as a key intermediate. ACC oxidase aminocyclopropanecarboxylate oxidase) is involved in the last step of ethylene biosynthesis. ACC oxidase is an enzyme that catalyzes ethyleneforming reactions. 

N-Triisopropylsilylethyiiyl pyrrole (77) could be alkylated with excellent C3 selectivity by protected amino cyclopropane 78 in the presence of scandium(III) triflate in excellent yield. Although most examples were conducted with indole substrates, both pyrroles and electron-rich arenes were compatible (130L3738). 

De Meijere showed that reactions of cyclopropylidene derivatives lead to amino-cyclopropane carboxylic acids via conjugate addition of an amine surrogate. Reac-... 

Acton GJ, Murray PB (1974) The roles of auxin and gibberellin in reversing radiation inhibition of hypocotyl lengthening. Planta 117 219-226 Adams DO, Yang SF (1979) Ethylene biosynthesis identification of 1-amino-cyclopropane-1-carboxylic acid as an intermediate in the conversion of methionine to ethylene. Proc Natl Acad Sci USA 76 170-174... 

Amides can also be employed as substrates. The mechanism in this case is subtly different to the mechanism involving the ester (Schemes 5.82-5.84). If the mechanism were the same, the amino group would be eliminated and the same product would be obtained. Instead, as with the LiAULr reduction of amides, the oxo group is eliminated, and the amino group is retained in the product, which is an amino cyclopropane 5.313. As with the esters, intramolecular Kulinkovich reactions are also possible (Schemes 5.85 and 5.86). ... 

Bower reported a directing group enhanced rhodium-catalyzed [(3-i-2)-i-l] cycloaddition reaction of nitrogen-tethered yne-CPs and CO (see (50)) [124]. The authors used the urea as the directing group to induce the oxidative addition at the proximal bond of the amino-cyclopropanes. 

Yamagami, T. et aL (2003) Biochemical diversity among the 1-amino-cyclopropane-l-carboxylate synthase isozymes encoded by the Arabidopsis gene family. J. Biol. Chem. 278,49102 9112... 

X 1-Amino-cyclopropane- apple Malus sylvestris Rosaceae... 

Waser and coworkers have reported the first use of amino cyclopropanes in [3+2]-cycloadditions with aldehydes to give amino tetrahydrofurans with high levels of diastereoselectivity (Scheme 22) [22]. A wide range of activators could be used in these reactions including normally inert Lewis acids like FeCL on AI2O3. In contrast to the Johnson et al. work mentioned above, racemic tetrahydrofurans resulted from the use of enantiomerically eiuiched aminocyclopropanes implying that the reaction proceeds through a zwitterionic intermediate. 

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