Reaction of the chiral amine (S)-N-α-(methylbenzyl)phenylallylamine, [(S)-N-α-mbpa], with nBuM (M = Li, Na, K) in the presence of the Lewis donors TMEDA or THF (TMEDA = N,N,N′,N′-tetramethylethylenediamine, THF = tetrahydrofuran) resulted in a series of mono-or dimetalated complexes, [{PhC(H)CH 3 NC(H)C-(H)C(H)PhLi 2 (TMEDA) 2 ] 1, [{PhC(H)CH 3 NCH CHCH 2 PhNa(TMEDA)] 2 2, and [PhC(CH 2 )N-(CH 2 CH 2 CH 3 )K] ∞ 3, being formed with various 1,3sigmatropic rearranged allylic bonding patterns. Completing previous work on the related amine N-α-(methylbenzyl)allylamine, the potassiated aza-enolate complex [(R)-{(PhC(CH 2 )N(CH 2 CH 2 CH 3 (THF)] ∞ 4 is also reported. All four complexes 1−4 have been characterized by single-crystal X-ray diffraction and solution NMR spectroscopy studies. DTF calculations on model systems investigated the preference for the monomeric Li 2 -mbpa 1 to undergo isomerization to the aza-allyl anion conformation, which, interestingly, is more energetically stable as a monomeric complex.

An unexpected aza-enolate propyl addition complex, [(PhCCH2)­(CHC­(CH2CH2CH3)­CH3)­NNa·THF]∞ (1), was isolated when (S)-N-α-(methylbenzyl)­allylamine reacted in hexane with nBuNa in the presence of THF. Analytical studies revealed a decomposition of the sodium 1-azaallylamide to a sodium enamide and propene, identified by solution studies and a GC-headspace study, respectively. Propene then adds to the carbanion tautomer of the sodium 1-azaallylamide followed by anionic rearrangements to later form the aza-enolate propyl addition complex.

The reaction of o-valerolactim ether with BuM (M = Li, Na, K) in the presence of the Lewis donors thf, tmeda, pyridine and pmdta resulted in the crystallisation and structural characterisation of a series of homo-and heteroanionic aggregates, which are also either homo or heterobimetallic. All the structures incorporate an aza-enolate (1-aza-allyl) anion (=R) derived from deprotonation of the lactim ether at the a-C, and its subsequent electronic rearrangement such that the metal bonds to the amido N. Lithiation resulted in crystals of [R 3 {R(Me 2 SiO)}Li 4 Á(thf) 4 ], 1, with Me 2 SiO À incorporated from the base induced decomposition of silicone grease; the linked dimer [R 4 Li 4 Á(tmeda) 3 ], 2, which has both terminal and bridging tmeda molecules; the octanuclear cluster [R 6 -m 6 -O-Li 8 Á(pyr) 2 ], 3, which is constructed around an O 2À anion; and [R(CH 2 QCHO) 2 Li 3 Ápmdta] 2 , 4, which incorporates lithium ethenolate, the base induced decomposition product of thf. Sodiation resulted in crystals of the simple dimeric complex [RNaÁtmeda] 2 , 5, while potassiation resulted in the heterobimetallic cluster [R(MeO)KLiÁ(tmeda)] 4 , 6, incorporating a MeO À anion due to its nucleophilic displacement from the valerolactim ether as MeOK by n Bu and subsequent anion exchange with t BuOLi. Solution NMR studies on the reaction between RH and t BuLi in the absence of a Lewis donor revealed that both the rate of deprotonation at the a-carbon and nucleophilic substitution of the ether functionality decrease substantially. The cyclic 2-t Bu-imine, as the thermodynamic product, becomes the dominant product, indicating that a Lewis donor solvent is necessary for efficient deprotonation to occur.

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