Tris amide

A similar in situ approach to alkoxide formation employs the readily accessible tris(amide)-Y(NTMS2)3, (293), and PrOI 1.881 In the absence of alcohol the polymerization of CL is fast but not controlled (Mw/Mn > 3). However, upon addition of alcohol, a controlled living system with polydispersities 1.1-1.2 results. At least 50 equivalents of PrOH may be added (the excess effects rapid chain transfer) with molecular weights in good agreement with theoretical values. Similar results have been reported using Nd(NTMS2)3, (294), and PrOH.882 The reactions of PrOH with (292) and (293) have both been studied by NMR, and in both cases Y5(/r5-0)(0 Pr)13 is not... 

Oxodi peroxymolyhdenum(hexamethy1phosphori c tri amide) Molybdenum, (hexamethylphosphoric tr1am1de)oxod1peroxy- (8) Molybdenum,... 

In principle, the same synthetic strategies as given for derivatives of D03A in Schemes 25 and 26 can be applied for tris(amides) of D03A according to formula 193. 

Under identical reaction conditions by using CS2CO3 it was possible to isolate 7b in quantitative yield as an NMR pure product, whereas by application of Rb2C03 only an impure product in 70% yield was obtained (Table 3) [19]. By addition of other alkali metal carbonates, even after ten days of reaction time, only unsatisfactory yields below 10% could be obtained, whereas in the synthesis of the tris(amide) 11 applying K2CO3 as base the yields of the Cs procedure were reached [27]. This was attributed to the insufficient basicities of these carbonates, which did not allow complete deprotonation of these tosylamides [19]. 

Very sterically crowded group 4 metal complexes bearing three or four amidate ligands can be synthesized via protonolysis (Figure 11). [34] The tris(amidate)... 

In a follow up report from Schafer s group [52a] in 2012, largely focused on studying the viscoelastic behavior of the polymer, a modified tris(amidate) yttrium complex was used to initiate ROP of e-caprolactone. This slightly bulkier complex with a diisopro-pylphenyl on the nitrogen instead of dimethylphenyl, gave lower molecular weight polymers of just under 1 x lO g/mol, but of a narrower polydispersity index (PDI) of around 1.5 compared with the values of between 2 and 2.5 achieved in previous studies. 

Syntheses and ion selectivities of the tri-amide derivatives of hexahomotrioxa-calix[3]arene. Remarkably large metal template effect on the ratio of cone vs. partial-cone conformers. H. Matsumoto, S. Nishio, M. Takeshita and S. Shinkai, Tetrahedron, 1995, 51, 4647. 

Secondary amides are versatile and highly accessible hydrogen bond donors that have been used in numerous synthetic receptors, hi the biological arena, there are many examples of proteins that employ amide NH- anion interactions to bind negatively charged guests [5-9]. The first example of a synthetic amide containing receptor, pubUshed in 1986 by Pascal and co-workers, was a crytpand-like tris-amide that was shown to interact with fluoride in DMSO-de [10]. 

In 1993, Reinhoudt and co-workers described the synthesis and binding properties of a series of tris-amides and tris-sulfonamides based upon the tren skeleton [11]. These receptors proved to be selective for phosphate in acetonitrile solution and demonstrated, arguably for the first time, that anion receptor systems need not be difficult to make but rather that simple organic compounds could function as very effective receptors. Stability constants were calculated by conductivity experiments and showed that receptor If bound dihydrogenphosphate with the highest affinity (14200 M ) in acetonitrile presumably due to the preorganization of the receptor via Jt-Jt interactions between the naphthyl groups. 

For example, the tris-amide CTV derivative 18 strongly binds OAc and weakly binds H2P04 in solution, but does not bind many other common anions. SAMs of 18 have been shown to act as a sensor for OAc . Similar amide binding sites are utilized in 19, where the ferrocene is an electrochemical reporter group for binding H2P04 and ATP anions. ... 

Rgure (a) Hydrogen bonds stabilized jc stacks (b) 1,3,5-benzene tris-amides. 

Di-t-butyl chromate and its pyridine adduct are suitable for large-scale oxidations of alcohols to ketones, thus cyclododecanol was converted into cyclododecanone (97 Alcohols are easily separated from non-hydroxylic compounds via their calcium chloride complexes. This method was used to separate cyclododecanone and cyclododecanol and is suitable for the separation of large quantities of material." All-cis-cyclododecane-l,5,9-triol was converted into the all-cis-tri-amine by tosylation, azide substitution, and reduction, and the amine acylated with 2,3-dimethoxybenzoyl chloride to give the tri-amide, an analogue of enterochelin. ... 

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