Ethane-1,2-diamine

Tliere are few examples for the preparation of imines from A-(l-haloalkyl)azinium halides and primary diamines. Among those reaetions reported, A-(ehlorophenylmethyl)pyridinium ehloride (33k), whieh has not been isolated, reaets with ethane-1,2-diamine and propane-1,3-diamine to afford the eorresponding diimines 72 (Seheme 22, 45-80%) (89JOC4808, 92BSB233). 

N-donor ligand. The reaction appears to proceed via an acyclic iminoplatinum(II) intermediate that undergoes a subsequent intramolecular cyclization. Some mechanistic aspects of this versatile reaction have been elucidated.225,226 A4-l,2,4-oxadiazolines have been prepared by the [2+3] cycloaddition of various nitrones to coordinated benzonitrile in m-[PtCl2( D M SO)(PhCN)] precursors.227,228 Racemic and chiral [PtCl2(PhMeSO)(PhCN)] complexes have also been used in order to introduce a degree of stereoselectivity into the reaction, resulting in the first enantioselective synthesis of A4-l,2,4-oxadiazolines, which can be liberated from the complexes by the addition of excess ethane-1,2-diamine. 

Attempts to prepare the primary amine complex Pt(C6F5)2en (en = ethane-1,2-diamine) by decarboxylation from PtCl2en and thallous pentafluorobenzoate in pyridine unexpectedly gave the organoamidoplatinum complex, [N,N -bis(2,3,5,6-tetrafluorophenyl)ethane-1,2-diaminato(2-) ] dipyridineplatinum(II) [Eq. (53)] (66). The proposed reaction sequence... 

Electrogenerated nickel(I)251 and cobalt(I)252 complexes of Salen (Salen = bis(salicylidene)ethane-1,2-diamine) have displayed good catalytic properties in the cleavage of carbon-halogen bonds in a variety of organic compounds. Recent research in this field has been reviewed.253... 

MePO2- or PME2- (Table XIX), but the open closed equilibrium lies very much on the side of the chelated form of the complex (87% for the Ca2+ complex - compare 15% for [Ca(atp)]2 and just 7% for [Ca(amp)] (695)). The availability of stability constants both for methylphosphonate and for benzimidazole (a purine model) complexes means that the chelate effect for complexes of (1H-benzimidazol-2-yl-methyl)phosphonate can be discussed without the usual complications, such as the differences between ethane-1,2-diamine and two ammonia or two methylamine ligands and disparities between units (704). 

To improve the rate of reduction the amino alcohol ligand of the ruthenium complexes was exchanged for monotosylated 1,2-diamine ligands. For exploratory experiments AT-tosylethane-1,2-diamine was prepared hy monotosylation of ethane-1,2-diamine and attached to the primary face of P-CD yielding 80. With P-CD as the only chiral unit the ruthenium complex of 80 could reduce aromatic and aliphatic standard ketones 63 and 69 in 91% 5deld, 25% ee (S) and 68% 5deld, 58% ee, respectively, within only 4h under standard conditions (Fig. 24). 

Fig. 12. (a) An octadentate tetra(3-hydroxy-2-pyridinone) chelator on an ethane-1,2-diamine template and (b) a hybrid desferrioxamine-3-hydroxy-2-pyridinone chelator. 

Sometimes ligands with two or more potential donor sites bond to two (or more) difierent central atoms rather than to one, forming a bridge between central atoms. It may not be necessary for the ligand in such a system to be like ethane-1,2-diamine, with two distinct potential donor atoms. A donor atom with two or more pairs of non-bonding electrons in its valence shell can also donate them to different central... 

This contains bis(monodentate) bridging ethane-1,2-diamine. 

In the names of amines, the general use of suffixes and prefixes is not always observed. Normally, the suffix -amine would be added to the name of the parent hydride and engender names such as methanamine (CH3-NH2). Further substitution on the nitrogen atom would then be indicated by prefixes, leading to names that appear very cumbersome, such as A -methylmethanamine for (CH3)2NH and N,N-dimethylmethanamine for (CH3)3N. The traditional names of methylamine, di-methylamine and trimethylamine are much simpler. In these names, the term amine is not a suffix. It is, in fact, the name of the parent hydride, NH3, which now serves as the basis of substitutive names. Names such as diethylamine and tributylamine are representative of the preferred nomenclature. Diamines are named accordingly, as with ethane-1,2-diamine for H2N-CH2-CH2-NH2 and propane-1,3-diamine for H2N-[CH2]3-NH2. There are allowed alternatives for these last two compounds ethylenediamine and propane-1,3-diyldiamine. 

N-Methyl-N, N, N -tris(2-pyridylmethyl) ethane-1,2-diamine, transition metal peroxides, 1072... 

Potential applications of molecular visualization include structures and processes not accessible by experiment. For example, [Co(en)3]3+ (en = ethane-1,2-diamine) can adopt four conformational isomers, lel3, lel2ob, ob2lel and ob3 (Fig. 6.1). Crystal... 

---