So far, in addition to halogen atoms, other non-metallic atoms can become part of the aromatic heterocycle, and the target ring system is still aromatic.Lothian-Tomalia, Mary K.; Hedstrand, David M.; Tomalia, Donald A.; Padias, Anne Buyle; Hall, H. K. Jr. researched the compound: Pentaerythrityltetrabromide( cas:3229-00-3 ).Category: imidazoles-derivatives.They published the article 《A contemporary survey of covalent connectivity and complexity. The divergent synthesis of poly(thioether) dendrimers. Amplified, genealogically directed synthesis leading to the de Gennes dense packed state》 about this compound( cas:3229-00-3 ) in Tetrahedron. Keywords: review divergent synthesis polythioether dendrimer; amplified genealog directed preparation dendrimer review; packed state de Genne dendrimer review; connectivity complexity dendrimer synthesis review. We’ll tell you more about this compound (cas:3229-00-3).
A review with 19 references on preparation of a poly(thioether) dendrimer (d-PTE) family using preformed branch cells in a genealogically directed synthesis (GDS) strategy with covalent bond amplification. Bicyclic orthoester functionality is introduced into a branch cell reagent (BCR) to temporarily mask pentaerythritol derived branch cells which are used to construct the interior of this new dendrimer family. These BCRs with multiplicities = 3 (Nb=3), are organized and amplified around an initiator core with multiplicity = 4 (Nc=4). The initiator core, pentaerythritol tetrabromide (Nc=4), is allowed to react with four equivalent of 4-acetothiomethyl-2,6,7-trioxabicyclo[2.2.2]octane (Nb=3) in the presence of base, to form the first generation possessing four bicyclic orthoester groups. After deprotection and transformation to bromide surface groups via tosylate intermediates, the second generation possessing twelve bicyclic orthoester groups is formed. Surprisingly, attempted displacement of all 36 surface groups at the third generation level showed that only one third of the end groups could be substituted. These exptl. data suggest that this (Nc=4, Nb=3) type dendrimer family exhibits de Gennes dense packing properties at the third generation level. Elemental anal., FTIR, H/C13 NMR spectroscopy and mass spectroscopy were used to confirm the structures. Mol. simulation data suggest that this dendrimer family should not undergo de Gennes dense-packing until the fourth generation. Steric requirements of the bulky mercaptomethyl anion used in the SN2 packing until the fourth generation. Steric requirement of the bulky mercaptomethyl anion used in the SN2 displacement of terminal bromides on this congested surface are proposed as the reason for incomplete formation of the third generation. This observation illustrates another example of “”sterically induced stoichiometry”” (SIS).
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Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem