Lithiation of a Cyclen‐Derived (NNNN) Macrocycle and Its Reaction with n‐Butyllithium

Abstract

Cyclic polyamine 1,4,7‐trimethyl‐1,4,7,10‐tetraazacyclododecane, (Me3TACD)H (1), was metalated with n‐butyllithium in pentane to give [Li2(Me3TACD)2] (2). The structure of this compound is dimeric in the solid state as shown by single‐crystal X‐ray diffraction. With an excess of nBuLi, nBuLi is incorporated into the product. Depending on the stoichiometry, the compounds [Li3(nBu)(Me3TACD)2] (3) or [Li4(nBu)2(Me3TACD)2] (4) are formed. As shown by single‐crystal X‐ray diffraction, both molecular structures show a ladder motif. (Me3TACD)H reacted with NaI/Na2CO3 in acetonitrile to give benzene‐soluble [NaI(Me3TACD)H] (5).

Can Cyclen Bind Alkali Metal Azides? A DFT Study as a Precursor to Synthesis

“…The cyclen unit of both the N 3 ‐end‐on and N 3 ‐side‐on structures adopts a C 4 (++++) conformation, as has recently been reported for crystal structures of three functionalised alkali metal‐cyclen complexes. These are the [Li(Me 4 cyclen)(OH 2 )][BAr F ], [Na(Me 4 cyclen)(thf)][BAr F ] and [Na(Me 3 cyclen)I] complexes, in which BArF=tetrakis(3,5‐trifluoromethylphenyl)borate, Me 4 cyclen=1,4,7,10‐tetramethyl‐1,4,7,10‐tetraazacyclododecane and Me 3 cyclen=1,4,7‐trimethyl‐1,4,7,10‐tetraazacyclododecane. The Li−N cyclen /Na−N cyclen bond lengths of these three crystal structures agree well with the corresponding bond lengths of the N 3 ‐side‐on structures Li‐2 a and Na‐2 a (Supporting Information, Tables S3 and S4).…”

“…The Li−N cyclen /Na−N cyclen bond lengths of these three crystal structures agree well with the corresponding bond lengths of the N 3 ‐side‐on structures Li‐2 a and Na‐2 a (Supporting Information, Tables S3 and S4). However, the distance between the basal plane of the cyclen ring and Li + /Na + ion is slightly larger in Li‐2 a and Na‐2 a (Table ), when compared with these distances in the three functionalised alkali metal‐cyclen complexes (0.758(7), 1.225(2) and 1.2803(11) Å, respectively).…”

Hypervalent Hydrosilicates Connected to Light Alkali Metal Amides: Synthesis, Structure, and Hydrosilylation Catalysis

“…In analogy to the synthesis of [Li(Me 3 TACD)] 2 ( 1 ), deprotonation of the macrocyclic polyamine ligand (Me 3 TACD)H with [Na( n Bu)], [KC 3 H 5 ], or [MCH 2 SiMe 3 ] (M=Na, K) at −30 °C gave [M(Me 3 TACD)(L)] n (M=Na, n =3, L=none ( 2 ), M=K, n =2, L=(C 6 H 6 ) 0.5 ( 3 )) (Scheme ). Highly basic alkyl reagents were required to prevent formation of stable adducts [{(Me 3 TACD)H}MR] due to the low acidity of the NH proton .…”

Rare‐Earth Metal Allyl and Hydrido Complexes Supported by an (NNNN)‐Type Macrocyclic Ligand: Synthesis, Structure, and Reactivity toward Biomass‐Derived Furanics

“…as an appropriate complexation agent for divalent copper and later for other metals 6a. 7a,b, 8 As a ten‐electron donor, Me 3 TACD − coordinates facially at trivalent rare‐earth metals and shields one hemisphere of the large metal center 7a,b. Alkyl and hydrido complexes of the smaller rare‐earth metals [Ln(Me 3 TACD)R 2 ] n (Ln=Sc, Y, Ho, Lu, R=CH 2 SiMe 3 , n =1 or Ln=Y, Ho, Lu, R=H, n =3) catalyze the hydrosilylation of α‐olefins 7a,b.…”

“…At room temperature, C s -symmetry on the NMR timescale is found for 1-Ce, 1-Nd, and 1-Pr, indicated by nine resonances in the 1 H NMR spectrum. [8]…”