Aminocyclopropanes ring opening

Karthikeyan S, Q Zhou, Z Zhao, C-L Kao, Z Tao, H Robinson, H-w Liu, H Zhang (2004) Structural analysis of Pseudomonas 1-aminocyclopropane-l-carboxylate deaminase complexes insight into the mechanism of a unique pyridoxal-5 -phosphate dependent cyclopropane ring-opening reaction. Biochemistry 43 13328-13339. 

A similar lactone ring opening is involved in the asymmetric synthesis of stereospecifically monodeuterated 1-aminocyclopropane-l-carboxylic... 

Cha s group [89] has recently developed a convenient method for the ring opening of tertiary aminocyclopropane tethered with an alkenyl moiety 199. The PET reaction of 199 led to formation of the five-membered bicyclic system 200 through a [3 + 2] annulation reaction in a good yield, as shown in Scheme 8.55. 

Numerous applications, especially in peptide chemistry, have taken advantage of this reactivity of BTI towards amides and peptidic amides [32], Here it may be added that A-protected aminocyclopropanic amides underwent ring-opening in their reaction with BTI (two equivalents) the /i-amino amide formed was obtained quantitatively on addition of benzyloxycarbonyl chloride (Z = PhCH2OCO) [33] ... 

During the reaction of the doubly activated allyl halides with primary and secondary amines no 2-amino-substituted cyclopropane derivatives could be isolated, but instead ring-opened products are formed. Primary amines give rise to the formation of aldimines (332) while secondary amines afford formally substitution products (333) . The formation of these products can be explained by ring cleavage of non-isolable electrophilic 2-aminocyclopropanes (331) as outlined in equation 104. 

Aminocyclopropanes (1) are typical representatives of the family of donor-substituted cyclopropanes. The combination of an amino moiety with the cyclopropane ring is not only of theoretical interest for possible donor-acceptor interactions, but is also the origin of an easy nucleophilic substitution of a group X in (1) or a ring-opening reaction. Intermediates 2 and 3 represent these two types of reactions according to the sequence 1 - 3 an aminocyclopropane is to be regarded as a homoenamine species. 

Hydride as a nucleophile converted 241 into the aminocyclopropanes 244 in fair yields. Here, a ring-opening reaction was prevented by removal of the acceptor carbonyl group in 242 by reduction (Scheme 6). A [2.1.0]-bicyclic system was accessible by this sequence too. 

Aminocyclopropanes were easily acylated by acid chlorides, isocyanates or isothiocyanates (e.g. Refs 3, 24, 27, 36, 71, 80, 82, 125, 178, 179, 184, 224). Polyureas, polyurethanes or polyamides have been prepared from 1,2-diaminocyclopropane Reduction of the carbonyl group in 423 by lithium aluminum hydride worked quite well for tertiary amides 5,473.495. longer reaction times effected a ring-opening in the case of a secondary amide (423, R = H) (LiAlH4 reduction of secondary... 

Substituent effects on the ring-opening reaction have been observed upon thermolysis of aminocyclopropanes (476) (equation 121). Compounds 478, which are derived from a homoenamine reaction, have been the only isolated products from heating 476 in the presence of On the contrary, NH4CI as a catalyst caused the ring-opening of the... 

Ring-opening reactions of the distal bond of aminocyclopropanes are of minor importance. Sometimes this type of reaction is observed in nucleophilic substitution of aminobicyclo[3.1.0]hexane derivatives (500) leading to 504 instead of (equation 128). The ring-opening tendency is a consequence of the lower stability of 501 with respect to other cyclopropaniminium ions. ... 

A primary amino function in aminocyclopropanes (413) can be removed easily by diazotation (for a review see Ref. 594). In the absence of any steric restrictions, displacement of the diazonium group led mainly to ring-opened allylic substitution products (579)3.4.11.53.84.86.144,147.595 (equation 150). Substituted cyclopropanes (580) are obtained only to a very small amount they were formed mainly (> 92 %) with inversion of configuration (see also Ref. 218). 

On the other hand the amino moiety in some bi- or polycyclic aminocyclopropanes could be substituted by diazotation without appreciable ring-opening 56.61,110.124,147,152 great steric influence of the diazonium group on the... 

The ring contraction of 2-halocyclohexanone enamines has been discussed in Section 4.3.12. The preparation of aminocyclopropane derivatives from the enamines of substituted a-chloro-cycloheptanones showed some restrictions. The substituent influences both the energy difference between the aminoallyl cation and cyclopropiminium ion and a subsquent homoenamine ring opening. 

Tertiary aminocyclopropanes are stable towards basic conditions. In contrast, primary aminocyclopropanes undergo facile ring opening when treated with base. Thus, reaction of 1-amino-1-methyl-2,2-diphenylcyclopropane with aqueous sodium hydrogen carbonate or methanolic sodium hydroxide at room temperature results in the formation of 4,4-diphenyl-butan-2-one as the sole product (Table 13, entry 5). Formation of the nitrogen anion by deprotonation, followed by ring opening to form the benzhydryl anion, can account for the reaction course. 

Reductive ring opening of A -monosubstituted aminocyclopropanes by lithium aluminum hydride has been reported. Thus, reduction of -amino-AT-methyl-2-phenylcyclopropane... 

The reaction of a simple primary amine, 1-aminocyclopropane, with aqueous lithium hypochlorite takes place readily at room temperature resulting in ring opening. Since the reaction competes with fragmentation to give ethene, the yield of 3-hydroxypropiononitrile, the ring-opened product, is modest (Table 15, entry 5). With 1-amino-1-methylcyclopropane, 4-hy-droxybutan-2-one is formed. 

Treatment of A-nitroso-iV-(cr5-2-phenylcyclopropyl)urea with excess sodium formate in methanol at 25 "C for 15 hours affords ( )-3-methoxy-l-phenylprop-l-ene (25%) and 3-methoxy-3-phenylprop-l-ene (60%, Table 15, entry 7). An almost identical result is obtained when the tran -isomer is used as substrate. Formation of the 2-phenylcyclopropyldiazonium ion, decomposition with loss of nitrogen to the 2-phenylcyclopropyl cation, followed by ring opening to form the phenylallyl cation, can explain the result. When [l- Hi]aminocyclopropane is subjected to deamination with nitrous acid in water at 0°C (Table 15, entry 8), allyl alcohol is obtained, which is isolated as the 4-(phenylazo)benzoate derivative in 44% yield. In this case, the deuterium is only located at the C2 allyl position. ... 

Aminocyclopropane derivatives are known to possess enzyme inhibitory properties.In particular, aminocyclopropanes are potent inhibitors of cytochrome P-450 mono-oxygenases. A carbon-centered free radical, generated by one-electron oxidation of aminocyclopropane by P-450 to form a nitrogen-centered radical cation and subsequent ring opening, may play an important role in the destruction of the enzyme. 

Encounter complexes between photoexcited 1-cyanonaphthalene and norbor-nadiene lead to products of several structural types. In polar solvents containing methanol, adducts are formed from exo-attack by methanol on the norboma-diene radical cation. In less polar solvents 1-cyanonaphthalene and norboma-diene form [2+2]adducts, exclusively on the norbomadiene exo-face. In non-polar solvents an endo-encounter complex between 1-cyanonaphthalene and norbomadiene is attacked by methanol from the exo-face to yield 1 1 1 adducts. SET to 1,4-DCB from readily accessible tertiary aminocyclopropanes yields cation radicals which undergo facile ring opening. A subsequent 1,5-hydrogen shift and hydrolytic workup provides ring-opened ketones for example E- or Z-(211) yields (212) in 85% yield. ... 

In this section we analyze information about metabolic cleavage or breakdown of cyclopropane rings in three instances the biosynthesis of irregular monoterpenes, the ringopening of cycloartenol (20) derivatives, and the metabolic opening of 1-aminocyclopropane-1-carboxylic acid (ACPC) (9) by two quite distinct fragmentation routes. We will not explicitly discuss the processing of presqualene pyrophosphate (77) and prephytoene pyrophosphate (89) to squalene (76) and phytoene (88) respectively, since those transformations have already been dealt with in Section II. 

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