Amines, inert leaving groups

Azetidines are often synthesized by reacting 1,3-dihalogenopropanes with an amine (ammonia gives poor yields), or from propane-1,3-diamines where one A-substituent can function as a leaving group. A reaction of the latter type is used to synthesize azetidine from A,A-bis(toluenesul-fonyl)-l,3-diaminopropane in two steps, the last being a reductive A-de-toluenesulfonation, caused by adding sodium to naphthalene in an inert solvent (Scheme 8.5). 

To our knowledge, no unambiguous results on the direct photochemical cleavage reactions of benzylic amines or amides have been reported. Presumably both of these leaving groups are very unreactive e.g., lV-(l-naphthylmethyl)aniline [69] and the naphthylmethylamides, 29 and 30 [70], are photochemically inert in... 

The substitution reactions of amine platinum(IV) complexes is appreciably slower than those of most other inert metal amines, at least in acidic solutions. Consequently, the availability of a relatively labile leaving group, such as trifluoro-methanesulfonate, may have advantages where substitution is required at the sixth site about the pentaammineplatinum(IV) ion. In parallel with reports of other second- and third-row complexes in this chapter, the synthesis of [Pt(NH3)5(0S02Cp3)] from the [Pt(NH3)5Cl]Cl3 precursor is readily achieved. Both are described below. 

Cationic alkene-Fp complexes are rather stable and easier to handle than their neutral alkene(tetracarbonyl)iron congeners. Due to their positive charge, they are inert towards electrophiles and, thus, can be employed as protecting groups for olefins. Bromination and hydrogenation of other double bonds in the molecule leaves them unaffected. On the other hand they readily react with various nucleophiles such as enamines, enolates, silyl enol ethers, phosphanes, thiols, and amines to give alkyl-Fp... 

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