Alkaline earth metal amides

Interaction of selenium with alkali metal amides and alkaline earth metal amides gives explosive products. 

An important class of alkali and alkaline earth metal amides are Mulvey s inverse crown complexes (also discussed in Chapter 2, dealing with sodium and potassium amides), in which cationic homo- or heterometallic macrocycles are hosts to anionic guest moieties.The term inverse crown indicates that the Lewis acidic/Lewis basic sites are reversed or exchanged in comparison to conventional crown ether complexes. Scheme 3.9 illustrates the range of recently published alkali and alkaline earth metal amide inverse crown complexes (for related Zn species see Chapter 7 on group 12 amides). 

The first well characterized alkaline earth metal amides were of the general formula [M N-(SiMe3)2 2L] (L = thf, (thf)2, or dme, M = Ca, Sr, and were synthesized in... 

Alkaline earth metal amides have a unique place in enolate chemistry in light of the preceding discussion. Yet, amides without steric demand—from NaNH2 to UNIT,—also are usually not suitable for the formation of enolates, since their nucleophilicities exceed their basicities. On the other hand, the amides LTMP, LDA, and LiHMDS (structures in Figure 4.18) are so bulky that they can never act as nucleophiles and always deprotonate C,H acids to the respective enolates. 

Tin-nitrogen bonded compounds are generally formed by reaction of an alkali or alkaline earth metal amide with an organotin halide compoundsofthe types R Sn(NR2)4- , ( = 1-3), (R3Sn) NR (n = 1-3), andcyc/o-(R2SnNR0 ( = 2 or 3) can be prepared (equation 79). Other routes include transaminations (equations 80 and 81). Tin carboxamides and snlfonamides have been obtained by reaction of tin oxides or hydroxides with amides (equation 82). 

Carbene complexes of alkaline earth metal amides and metallocenes have also been reported. Reaction of calcium, strontium, and barium bis(trimethylsilyl)amides [M(N(SiMe3)2 2(thf)2] (M = Ca, Sr, Ba) with two equivalents... 

To further examine the nucleophilic side of the CH activation continuum, the our group and the Cundari group undertook a computational study [59] of alkali metal amide and alkaline earth metal amide CH activation reactions with alkanes. This study is directly related to classic superbase chemistry using cesium cyclohexylamide-type reagents to induce CH bond deprotonation of alkanes [60]. 

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