N- Allylamines

In 1950, Cope and coworkers48 unsuccessfully attempted to use the well-known Meisenheimer rearrangement of N-allylamine oxides to 0-allylhydroxylamines49 in performing the formally analogous rearrangements of allyl aryl sulfoxides to allyl arenesulfenates and of allyl aryl sulfones to allyl arenesulfinates (equations 11-13). 

Radical cyclization is compatible with the presence of other functional groups. Treatment of XCH2CON(R)-C(R )=CH2 derivatives (X = Cl, Br, 1) with Ph3SnH and AIBN led to formation of a lactam via radical cyclization. " Cyclization of N-iodoethyl-5-vinyl-2-pyrrolidinone led to the corresponding bicyclic lactam, " and there are other examples of radical cyclization with molecules containing a lactam unit " or an amide unit. Radical cyclization occurs with enamines as well. Photochemical irradiation of A,A-dialIyl acrylamide leads to formation of a lactam ring, and in this case thiophenol was added to generate the phenylthio derivative. Phenylseleno N-allylamines lead to cyclic amines. co-Iodo acrylate esters cyclize to form lactones. " ... 

Anthraquinone photosensitised irradiation of tertiary N-allylamines in the presence of aP-unsaturated esters gives good yields of lactams. Using pyrex-filtered output (X>290 nm) from a 450 W medium pressure Hanovia lamp, for example, A-allylpiperidine and methyl methacrylate reacted in acetonitrile to give a 2 3 diastereomeric mixture (2S, 9S 2R, 95) of the indolizidone 1. 

The allylic amines 30e and 31d were obtained in 87% and 75% yield, respectively. N-Alkylation and subsequent treatment with methylamine-40% water or pure butylamine gave the corresponding N-methyl-N-allylamine 42 and 43 in good overall yield. 

For example, (C5Me5)RuCl(cod) showed high catalytic activity for allylic substitution by amines (heteroatom nucleophiles that fail with Mo and W catalysts) under extremely mild reaction conditions (0 °C, for 1 h >99% yield). The reaction is also highly regioselective to give branched N-allylamines as a major product (Eq. 5.31) [29]. 

Sensitizers such as benzophenone, anthrone and xanthene were also observed to catalyze these reactions [327]. Anthraquinone sensitized photoreactions of N-allylamines with a,jff-unsaturated esters also yield lactams as the main product. Minor amounts of tandem radical addition products were also formed [328]. 

---