Of bicyclic amines

The IH of exocyclic alkenes allows the construction of bicyclic amines bearing one methyl group at the ring junction. Although long reaction times (2-7 days) are necessary (Eq. 4.22), amines are obtained in good yield. In contrast, endocyclic aminoalkenes are resistant to cyclization [134]. 

The enantioselectivity of Sn(II) enolate reactions can be controlled by chiral diamine additives. These reagents are particularly effective for silyl thioketene acetals.162 Several diamines derived from proline have been explored and l-methyl-2-(l-piperidinomethyl)pyrrolidine 21 is an example. Even higher enantioselectivity can be achieved by attachment of bicyclic amines to the pyrrolidinomethyl group.163... 

Lehn and Sauvage (34) suggest that bicyclic ligands should be better suited than non-cyclic polyethers to selectively complex cations. Their data (Table 8) show this to be valid for the series of bicyclic amines represented by the structures in Fig. 3. 

Scheme 2.11. Basicity of bicyclic amines substituted with electron-withdrawing groups [39],...

This possibility of the ion pair to collapse, proved for several systems, was not consido ed in the polymerization of bicyclic amines initiated for instance with ethyl bromide. The assumed structure of the cationated conidine is > ... 

As expected, the influence of the halogen in a-halo ketones strongly influences the course of the reaction. At — 10°C, 2-chlorocyclohexanone reacted with pyrrolidine to give the isolable intermediate amino-substituted allylic chloride 6 (X = Cl) in 85% yield, along with 15% of bicyclic aminal. The corresponding a-bromo ketone showed the expected tendency for further ring closure into the cyclopropanone aminal 7, while a-fluorocyclohexanone was completely transformed into the allylic fluoride 6 (X = F). ... 

The reaction of monooxo C-H acids such as acetone/ ethyl methyl ketone,or cyclo-pentanone with monocyclic A, 0-acetals or bicyclic A, 0-acetals or aminals gave the expected substitution products 1. Aqueous buffer solutions of pH 5.5 were reported to be sufficient for activation of bicyclic aminal precursors. Monocyclic aminal or hemiaminal starting materials were less reactive. Remarkably, methyl cyanoacetate could not be aminocyclopropylated. The sterical course of the reaction of bicyclic derivatives was not determined. 

An interesting study reported in 2001, although it did not utilize any inverse-detected 2D NMR data, did report a wealth of useful chemical shift data for parent azoles and benzazoles. Solid-state chemical shift data were reported for several pyrazole analogues by Alvarez-Larena. Trofimenko et al reported a study of the buttressing effects of the A-tert-h xiy group of a series of pyrazoles in the solid state, followed by a study by Claramunt and co-workers of a series of halo triazoles. Martins and co-workers reported data for a series of 5-trichloromethyl-1,2-dimethyl-1/f-pyrazolium chlorides. Malpass and co-workers reported direct observe chemical shift data for a series of bicyclic amines and lactams. Recently, a large body of chemical shift data for a series of l,4-diazaspiro[4.5]decanes and l,4-oxazaspiro[4.5]-decanes using direct observe methods were reported by Ariza-Castolo and co-workers. " Readers with an interest in the chemical shift behavior of these systems are directed to these references as a source of data. 

A number of applications of the above-presented approach have been made in the synthesis of bicyclic amines. It has been used in the preparation of pyrrolo[l,2-a]indoles starting from N-trimethylsilylmethyl indoles, which are reacted with silver fluoride in an oxidation-reduction reaction to provide the desired products in good to excellent yields126 (equation 128). This same approach was applied to the preparation of some... 

Nelson s detailed investigation of one-electron oxidation of bicyclic amines and hydrazines continues CV studies show that /V -diacyl-hydrazines (19)30a and azabicyclooctanes (20a)30b gjVe long-lived radical cations comparison has been made between ease of electron loss and N inversion barriers in (20b) and related N-chloroamines 30c studies of the nitroxides (21) and related compounds show that ff-coupied transmission of positive charge from N to the CO in the radical cation is unimportant. 30d... 

Table 26. Electrochemical fluorination of bicyclic amines (69ZOB2716, 91JFC(51)53)...

The thermal cyclization of bicyclic amine 178 showed selective endo-cyclization to 179, which was an intermediate in the formal total synthesis of... 

Electrochemical oxidaticai of bicyclic amine prepared from (5)-prolinol and trifluoroace-taldehyde proceeded to afford enantiomerically pure methoxylated compound in excellent regioselectivity. This product was easily... 

Clark JS, Hodgson PB, Goldsmith MD et al (2(K)1) Rearrangement of ammonium ylides produced by intramolecular reaction of catalytically generated metal carbenoids. Part 2. Stereoselective synthesis of bicyclic amines. J Chem Soc Ptakin Trans 1 3325-3337 Miyashi T, Nishizawa Y, Fujii Y et al (1986) The intramolecular nitrene-type 1, 1 -cycloaddition reaction of allyl-substituted diazomethanes. J Am Chem Soc 108 1617-1618... 

The potentials (Ep) observed for 1 and 2 are more positive than for the tropane (1.07 V) and nortropane (1.35 V) models -. The difference is likely due to the methyl ester group. Thus, tropacocaine, which is identical to 1 except for the absence of that substituent, oxidizes at 1.05 V24. Previous studies s of bicyclic amines containing a Y carbonyl have shown an adverse effect on oxidation. For example, with 9-azabicyclo [3.3.1]nonan-3-one compounds (cyclic ketones with carbonyl y to amine) oxidation was 0.2 V more difficult than for the corresponding methylene... 

The hydroamination/bicyclization of diaUcenylamines, dialkynylamines and alken-ylalkynylamines opens a straightforward route to a family of bicyclic amines in a tandem C-N and C-C bond-forming process. An important prerequisite for the success of this reaction sequence is a sufficient lifetime of the metal alkyl intermediate formed in the initial insertion process of the alkene/alkyne in the metal-amide bond in order to permit the carbocyclization step. Close proximity of the unsaturation to the metal-amide moiety allows facile bicyclization over protonolysis leading to the normal hydroamination product. Lanthanocene catalysts have been found applicable for this transformation (Scheme 13) [23,139]. 

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