78108-84-6Relevant academic research and scientific papers
Effects of phosphorus substituents on reactions of α- alkoxyphosphonium salts with nucleophiles
Goto, Akihiro,Otake, Kazuki,Kubo, Ozora,Sawama, Yoshinari,Maegawa, Tomohiro,Fujioka, Hiromichi
, p. 11423 - 11432 (2012/11/07)
The effects of phosphorus substituents on the reactivity of α-alkoxyphosphonium salts with nucleophiles has been explored. Reactions of α-alkoxyphosphonium salts, prepared from various acetals and tris(o-tolyl)phosphine, with a variety of nucleophiles proceeded efficiently. These processes represent the first examples of high-yielding nucleophilic substitution reactions of α-alkoxyphosphonium salts. The reactivity of these salts was determined by a balance between steric and electronic factors, respectively, represented by cone angles θ and CO stretching frequencies ν (steric and electronic parameters, respectively). In addition, a novel reaction of α-alkoxyphosphonium salts derived from Ph3P with Grignard reagents was observed to take place in the presence of O2 to afford alcohols in good yields. A radical mechanism is proposed for this process that has gained support from isotope-labeling and radical-inhibition experiments. A dramatic change in the reactivity of an α-alkoxyphosphonium salt toward nucleophiles is observed due to the steric and electronic nature of the phosphine substituents. By changing the type of phosphorus substituents, the reaction pathway can be controlled to proceed selectively by substitution or a new radical reaction (see scheme; OTf=trifluoromethansulfonate, TMS=trimethylsilyl, o-tol=tolyl). Copyright
Combination of RCM and the Pauson-Khand reaction: One-step synthesis of tricyclic structures
Rosillo, Marta,Arnaiz, Eduardo,Abdi, Delbrin,Blanco-Urgoiti, Jaime,Dominguez, Gema,Perez-Castells, Javier
experimental part, p. 3917 - 3927 (2009/04/07)
The combination of ring-closing metathesis (RCM) followed by an intramolecular Pauson-Khand reaction gives direct entry to tricyclic compounds. The RCM was carried out on a hexacarbonylcobalt-complexed alkyne, this complex acting as a protecting group against enyne metathesis. The procedure was studied for dienynes containing heteroatoms and allows the building of [6,5,5] and [7,5,5] tricyclic systems. The feasibility of the process depends strongly on the nature of the substrate. Wiley-VCH Verlag GmbH & Co. KGaA, 2008.
STEREOSELECTIVE SYNTHESIS OF THE TRICYCLIC CONDENSED DERIVATIVES OF THIAZOLIDINE
Sokolov, V. V.,Potekhin, A. A.,Ovchinnikova, I. V.,Gindin, V. A.,Smirnov, S. N.
, p. 582 - 589 (2007/10/02)
The perhydro derivatives of thiazoloquinoline, thiazolocyclopentapyridine, thiazoloindole, and cyclopentapyrrolothiazole and also their 2-methyl derivatives were synthesized by the addition of thiirane and methylthiirane at the C=N bond in bicyclic imines of the 2,3,4,4a,5,6,7,8-octahydroquinoline type.An alternative method involves reaction of the thiiranes with amino ketones of the 2,2-ethylenedioxycyclohexylpropylamine type, protected at the carbomyl group, followed by acid deblocking and cyclization by treatment with alkali.The last method is the only method for the production of perhydrocyclopentapyrrolothiazoles, since 2,3,3a,4,5,6-hexahydrocyclopentapyrrole is not a stable imine.Some of the compounds were obtained in the form of single diastereomers, the configurations of which for the two subjects were determined by NMR.In other cases mixtures of the stereoisomers are formed with a srtong preponderance of one of them; arguments concerning their configurations are presented.It is shown that both methods of synthesis lead to an identical stereochemical result.
Synthesis of (+/-)-Nitramine and (+/-)-Isonitramine
Carruthers, William,Moses, Roger C.
, p. 1625 - 1628 (2007/10/02)
The alkaloids (+/-)-nitramine (1; R=H) and (+/-)-isonitramine (2; R=H) have been synthesized, employing an intramolecular Mannich rection to set up the spirocyclic ring system.
