Nucleophilic substitution 3 + 4 / cycloadditions

N-alkylation, 4, 236 Pyrrole, 2-formyl-3,4-diiodo-synthesis, 4, 216 Pyrrole, 2-formyl-1-methyl-conformation, 4, 193 Pyrrole, 2-formyl-5-nitro-conformation, 4, 193 Pyrrole, furyl-rotamers, 4, 546 Pyrrole, 2-(2-furyl)-conformation, 4, 32 Pyrrole, 2-halo-reactions, 4, 78 Pyrrole, 3-halo-reactions, 4, 78 Pyrrole, 2-halomethyl-nucleophilic substitution, 4, 274 reactions, 4, 275 Pyrrole, hydroxy-synthesis, 4, 97 Pyrrole, 1-hydroxy-cycloaddition reactions, 4, 303 deoxygenation, 4, 304 synthesis, 4, 126, 363 tautomerism, 4, 35, 197 Pyrrole, 2-hydroxy-reactions, 4, 76 tautomerism, 4, 36, 198... 

Thieno[3,4-d][ 1,2,3]triazole, tetramethyl-synthesis, 6, 1015 Thieno[3,4-c][ 1,2,3]triazoles synthesis, 6, 1042 Thieno[3,4-d][ 1,2,3]triazoles reactions, 6, 1036 synthesis, 6, 1044 Thienyl radicals generation, 4, 832 Thiepane, 2-acetoxy-synthesis, 7, 574 Thiepane, 2-chloro-nucleophilic substitution, 7, 573 synthesis, 7, 574 Thiepane, 2-methyl-synthesis, 7, 573 Thiepane, 2-phenyl-synthesis, 7, 573 Thiepane, 3,3,6,6-tetramethyl-cycloaddition reactions, 7, 574 Thiepanes, 7, 547-592 applications, 7, 591... 

The direct, stereoselective conversion of alkynes to A-sulfonylazetidin-2-imines 16 by the initial reaction of copper(l) acetylides with sulfonyl azides, followed, in situ, by the formal [2+2] cycloaddition of a postulated A-sulfonylketenimine intermediate with a range of imines has been described <06AG(E)3157>. The synthesis of A-alkylated 2-substituted azetidin-3-ones 17 based on a tandem nucleophilic substitution followed by intramolecular Michael reaction of primary amines with alkyl 5-bromo-4-oxopent-2-enoates has been... 

Thiazyl halide monomers undergo a variety of reactions that can be classified under the general headings (a) reactions involving the 7i-system of the N = S triple bond, (b) nucleophilic substitution, (c) halide abstraction, and (d) halide addition. The cycloaddition of NSF with hexafluoro-1,3-butadiene provides an example of a type (a) reaction. 

Tandem nucleophilic substitution-[2+3] cycloaddition reaction of 4-bromo- and 4-toluenesulfonyloxy aldehydes 77 with sodium azide in DMF at 50 °C affords excellent yields (>80%) of substituted pyrrolo[.2.3.4]oxatriazoles 78 (Scheme 8) <2002HAC307>. 

Keywords Absolute configuration, Amines, Amino acids, Carbenes, Cascade reactions, 2-chloro-2-cyclopropylideneacetates. Combinatorial libraries. Cycloadditions, Cyclobutenes, Cyclopropanes, Diels-Alder reactions. Heterocycles, Michael additions. Nitrones, Nucleophilic substitutions, Peptidomimetics, Palladium catalysis. Polycycles, Solid phase synthesis, Spiro compounds. Thiols... 

In conjunction with this, Jeong reported the cycloadditions of bis(allyl) and bis(homoallyl) acetals of alkynals leading to bicyclic lactols. Smaltz extended its utility to the synthesis of carbocyclic nucleoside by coupling with nucleophilic substitution of a 7r-allylic palladium complex (Equation (46)). ... 

The purpose of this review is to present in some detail a simple, qualitative framework for understanding the factors which go into the creation of a reaction profile. Since the question raised is so fundamental - What determines the barrier in any chemical reaction - the model encompasses within its single structure reactions as different as electron-transfer reactions, e.g., (1) and (2), nucleophilic substitution (3), cycloadditions (4), proton transfer... 

The major classes of photochemical reaction for aromatic compounds are nucleophilic substitution and a range of processes that lead to non-aromatic products—valence isomerization, addition or cycloaddition reactions, and cyclization involving 6-electron systems. These five general categories of reaction will be described in the following sections, together with a few examples of more specific processes. 

Oxidation reactions, Diels-Alder cycloadditions (with subsequent dehydration of the adducts to benzanthrones) and nucleophilic substitution reactions have also been reported. Probably these condensed isobenzofu-... 

Quinolines have also been prepared on insoluble supports by cyclocondensation reactions and by intramolecular aromatic nucleophilic substitution (Table 15.26). Entry 10 in Table 15.26 is an example of a remarkable palladium-mediated cycloaddition of support-bound 2-iodoanilines to 1,4-dienes. Reduction of the nitro group of polystyrene-bound 2-nitro-l-(3-oxoalkyl)benzenes with SnCl2 (Entry 11, Table 15.26) leads to the formation of quinoline /Y-oxides. These intermediates can be reduced to the quinolines on solid phase by treatment with TiCl3. 4-Quinolones have been prepared by thermolysis of resin-bound 2-(arylamino)methylenemalonic esters [311]. 

The quinones have excellent redox properties and are thus important oxidants in laboratoty and biological symlions. The presence of an extensive array of conjugated systems, especially the a, /(-unsaturated ketone arrangement, allows the quinones to participate in a variety of reactions. Characteristics of quinone reactions include nucleophilic substitution electrophilic, radical, and cycloaddition reactions photochemistry and normal and unusual carbonyl chemistry. 

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