Pyrrole-based silane

Pyrrole-based silane primer for corrosion protection of... 

A pyrrole-based silane has been reported to promote polypyrrole (Ppy) adhesion on insulating substrates such as n-type silicon photoanodes [10], p-type silicon wafers [11] and glass fibres [12]. To the authors knowledge, this approach has not been used with reactive metals. If both ECPs and silane compounds are combined in a single coating, it should be possible to obtain a composite film with improved corrosion protection, chemical/mechanical stability and adhesion. In the end, simplification of the deposition and processing of ECPs would be feasible. 

This work describes a surface treatment on as-received commercial aluminium alloys with a pyrrole-based silane (SiPy). Coatings on 6082-T6, 5083-H111 and 2024-T3 alloys were deposited following the classical steps for silane deposition, i.e. hydrolysis and condensation. The corrosion behaviour was assessed in chloride-containing... 

The pyrrole-based silane (SiPy) molecule is schematically represented in Fig. 5.1. A SiPy solution was prepared at 4%v/v in methanol/water (95 5) with pH adjusted to 4 by adding acetic acid (10%). Methyltrimethoxysilane (Si) solution was prepared similarly. 

In planning a diversity-oriented synthetic panel of constitutionally and stereochemically diverse anomeric 4a-carbafuranosylamines, our research group remained faithful to the general plan delineated in Scheme 2 (vide supra), by utilizing the pyrrole-based dienoxy silane 76 as the pivotal amine source [7b,e]. 

Polymeric Viologen Systems. The write-erase efficiency of an ECD using for example aqueous MV would be low since both the dicationic and radical-cation states are very soluble. Improved MV-based systems may be made by retarding the rate at which the radical-cation product of electron transfer diffuses away from the electrode by use of an anionic polyelectrolyte such as poly(2-acrylamido-2-methylpropane-sulfonic acid) (polyAMPS) (46,47) or the sulfonated perfluorinated polyether, Nafion (48). An alternative approach is the surface modification of an electrode using silanization methodology (49), a preformed polymeric viologen salt (50) or oxidative electropolymerization of a pyrrole-substituted viologen (51) (Fig. 5). 

Curti C, Ranieri B, Battistini L, Rassu G, Zambrano V, Pelosi G, Casiraghi G, Zanardi F (2010) Catalytic, asymmetric vinylogous mukaiyama aldol reactions of pyrrole- and furan-based dienoxy silanes how the diene heteroatom impacts stereocontrol. Adv Synth Catal 352 2011-2022... 

Based on the mechanistic investigation and chemistry of reactive intermediates in zirconocene-mediated reactions, the author subjected organic azide to the reaction and developed a one-pot synthesis of pyrrolo[3,2-if]pyridazine derivatives via zirconocene-mediated cyclization of one bis(alkynyl)silane, two nitriles, and one azide. When TMSN3 was used as a special azide, pyrrole-2,3-diones were isolated in high yields. These functionalized pyrrole-2,3-diones could be eflhciently further transformed into pyrrole-fused heterocycles (Scheme 2.13). 

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