Intramolecular reaction

About: Intramolecular reaction is a research topic. Over the lifetime, 5015 publications have been published within this topic receiving 138213 citations.

Nickel(0)-Catalyzed Intramolecular [4 + 4] Cycloadditions: 5. The Type II Reaction in the Synthesis of Bicyclo[5.3.1]undecadienes

Abstract: The preparation and type II intramolecular [4+4] cycloaddition of a bis-diene is described in connection with studies on the synthesis of taxol (I), crispolide (2), and vulgarolide (3). The required bis-diene is prepared by a carboalumination of an alkyne, giving an iodide which is then coupled in the presence of palladium to a vinyltin to give a stereodefined diene. Elaboration of this system involves the reaction of 2-lithio-1,3-butadiene with a dienal to give a bis-1,3-diene tethered at the terminus of one diene and the internal position of the other.Cycloaddition of this bis-diene mediated by a nickel(0)/tri-O-biphenyl phosphite catalyst provides a bicyclo[5.3.1]undecadiene,a ring system common to a variety of complex molecules.

Synthesis of the core ring system of the yuzurimine-type Daphniphyllum alkaloids by cascade condensation, cyclization, cycloaddition chemistry.

Abstract: Addition of hydroxylamine to substituted 4-chlorobutanals gives intermediate nitrones that undergo tandem cyclization and then intramolecular dipolar cycloaddition to give the core ring system of the yuzurimine-type natural products. Ring-opening of the isoxazolidines gives amino alcohols that can be converted to 1,3-oxazines, representing the tetracyclic core of alkaloids such as daphcalycic acid and daphcalycine.

Heterocycles from Nitrile Imines. Part 1. 1,2,3,4-Tetrahydro-1,2,4,5-Tetrazines

Abstract: Syntheses des s-tetrazines du titre a partir de methylhydrazones d'acetone ou cyclanones et de [N-aryl chloro] formohydrazonoyl formiates de methyle ou de chlorures de N-aryl benzohydrazonoyle (precurseurs de nitrilimines)

Cyclization of 2-[N-(methylsulfonyl)anilino]acetaldehyde diethyl acetals to indoles. Evidence for stereoelectronic effects in intramolecular electrophilic aromatic substitution

Abstract: Influence de la temperature et des substituants sur le cycle anilino sur la reaction de cyclisation du titre; cyclisation analogue de diethylacetals de N-mesylanilino-3 propanals en mesyl-1 tetrahydro-1,2,3,4 quinoleines