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Alkene substrates with a tethered nitrogen nucleophile have been used in these transformations to promote intramolecular aminocyclization. [5] [6] While intermolecular carboamination is extremely hard, people have developed a strategy to combine the nitrogen and carbon part, which is known as the third class. The most general carboamination ...
A nitrogen bound to both a good electrofuge and a good nucleofuge is known as a nitrenoid (for its resemblance to a nitrene). [2] Nitrenes lack a full octet of electrons are thus highly electrophilic; nitrenoids exhibit analogous behavior and are often good substrates for electrophilic amination reactions.
Cyclohexene derivatives, such as imines, epoxides, and halonium ions, react with nucleophiles in a stereoselective fashion, affording trans-diaxial addition products. The term “Trans-diaxial addition” describes the mechanism of the addition, however the products are likely to equilibrate by ring flip to the lower energy conformer, placing the new substituents in the equatorial position.
A wide variety of carbohydrates, as well as nitrogen nucleophiles (ex. amino acids), can be used to furnish highly stereochemically enriched products. The aminopolyol products can then undergo further reactions to prepare aminosugars. Petasis used this reaction to prepare Boc-protected mannosamine from D-arabinose. [19]
Nucleophiles preferentially add to even-hapticity polyene ligands at a terminus. [1] Nucleophiles add to odd-hapticity acyclic polyene ligands at a terminal position if the metal is highly electrophilic, otherwise they add at an internal site. Simplified: even before odd and open before closed
Others, however, insist that such a usage is an abuse of terminology, and limit the Michael addition to the formation of carbon–carbon bonds through the addition of carbon nucleophiles. The terms oxa-Michael reaction and aza-Michael reaction [2] have been used to refer to the 1,4-addition of oxygen and nitrogen nucleophiles, respectively. The ...
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This reaction differs from a common S N 2 reaction, because it happens at a trigonal carbon atom (sp 2 hybridization). The mechanism of S N 2 reaction does not occur due to steric hindrance of the benzene ring. In order to attack the C atom, the nucleophile must approach in line with the C-LG (leaving group) bond from the back, where the ...