Analogical approaches ring opening

II Analogical approaches A Analogy by ring opening open-chain 215... 

The rate of disappearance of the starting materials was followed as one approach to determine the effect of catalyst type and concentration on the rate of the ring-opening polymerization. Results are presented in this chapter for the potassium-siloxanolate-catalyzed system, as well as for the analogous tetramethylammonium- and tetrabutylphosphonium-siloxanolate-catalyzed systems. 

Reduction of the ketone moiety and ring opening with aqueous HBr gave statine93 This fundamental approach was later used to prepare both statine and an analogous cyclohexyl derivatives ... 

Approaches to the preparation of functionalized sucdnimides and their ring-opened analogs via intra-moiecular carbonylation of fluoroamide-directed sp -hybridized C—C bonds represent an important step forward for Pd(II) catalysis and can provide direct access toward the preparation of differentiated 1,4-dicarbonyl compounds a common structural motif in complex molecule synthesis (Schane 3.27). ... 

There are several approaches to the synthesis of heterochain PCSs, which can be divided into three large groups chain ring opening and vinyl polymerizations, step-growth reactions (polymerization and polycondensation), and polymer-analogous transformations. 

With a similar rationale, Cai and coworkers tried to expand the product library by aiming for structural analogs of the widely applied 1,4-benzoxazepines [42]. These seven-membered rings are usually synthesized in a multistep process, but are now available from three simple starting materials in a palladium-catalyzed multicomponent approach. The reaction cascade is initiated by deprotonation and successive ring opening of the electron-poor aziridine 167 by the phenolate 168. Oxidative addition of palladium to the aryl iodide allows isocyanide insertion to furnish 172. Base-induced... 

The synthetic strategies for the incorporation of cleavable moieties into the backbone of PEG that have been employed to date (Table 2) mirror the inherent challenges related to this task. The most appreciated approach would be direct synthesis via the anionic ring-opening polymerization (AROP) of ethylene oxide (EO), with an oxirane co-monomer providing the additional functionality (analogous to the synthesis of multifunctional PEGs [38]) since copolymers can be... 

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