93652-37-0Relevant academic research and scientific papers
Acid-Catalyzed O-Glycosylation with Stable Thioglycoside Donors
Lacey, Kristina D.,Quarels, Rashanique D.,Du, Shaofu,Fulton, Ashley,Reid, Nicholas J.,Firesheets, Austin,Ragains, Justin R.
supporting information, p. 5181 - 5185 (2018/09/12)
Two classes of thioglycoside, 4-(4-methoxyphenyl)-3-butenylthioglycosides (MBTGs) and 4-(4-methoxyphenyl)-4-pentenylthioglycosides (MPTGs), undergo acid-catalyzed O-glycosylations with a range of sugar and nonsugar alcohols at 25 °C. Electron density at t
Palladium-catalyzed allylic cross-coupling reactions of primary and secondary homoallylic electrophiles
Stokes, Benjamin J.,Opra, Susanne M.,Sigman, Matthew S.
, p. 11408 - 11411 (2012/09/05)
The Pd(0)-catalyzed allylic cross-coupling of homoallylic tosylate substrates using boronic acids and pinacol esters is reported. The reaction uses 2-(4,5-dihydro-2-oxazolyl)quinoline (quinox) as a ligand and is performed at ambient temperature. The scope of the reaction is broad in terms of both the boronate transmetalating reagent and the substrate and includes secondary tosylates. Mechanistic studies support an alkene-mediated SN2-type stereoinvertive oxidative addition of unactivated primary and secondary alkyl tosylates.
A mechanistic alternative for the intramolecular hydroboration of homoallylic amine and phosphine borane complexes
Scheideman, Matthew,Shapland, Peter,Vedejs, Edwin
, p. 10502 - 10503 (2007/10/03)
Intramolecular hydroboration is demonstrated starting from homoallylic amine boranes upon activation by iodine. The process involves a B-iodoborane complex as the intermediate and may occur via internal displacement of iodide by the alkene to generate a cationic borane-alkene π-complex on the way to hydroboration products. The reaction can be carried out using a catalytic amount of iodine. Copyright
Regiochemical and Stereochemical Studies on Halocyclization Reactions of Unsaturated Sulfides
Ren, Xiao-Feng,Turos, Edward,Lake, Charles H.,Churchill, Melvyn Rowen
, p. 6468 - 6483 (2007/10/03)
The regiochemistry and stereochemistry for the halocyclization reactions of unsaturated benzyl sulfides have been examined as a function of tether length, type of unsaturation (carbon-carbon double bond versus carbon-carbon triple bond), substituents, and halogenating agent.Alkenyl sulfides were found to react with iodine or bromine at room temperature to give five-membered ring cycloadducts exclusively over those having four-membered rings, while for larger systems, six-membered ring products are formed preferentially over their five-membered ring isomers and exclusively over the seven-membered ring adducts.The endo- versus exo-regioselectivity of these alkenyl sulfide ring closure most likely reflects the difference in thermodynamic stabilities of the β-halo sulfide cycloadducts, which are able to equilibrate via a common episulfonium intermediate.The efficiency of cyclization process markedly drops off for these alkenyl sulfides as the tether length increases beyond four intervening carbon centers.Thus, while the halogenations of 3-butenyl sulfides and 4-pentenyl sulfides give high yields of cycloadducts, those of 5-hexenyl sulfides afford only small amounts of cyclized products and large quantities of acyclic dibromides.Conversely, the reactions of acetylenic sulfides with iodine give uniformly high yields and regiochemical control regardless of the tether length.Thus, 3-butynyl and 4-pentynyl sulfides cyclize cleanly to the five-membered ring while 5-hexynyl sulfides give exclusively the six-membered ring.The products arising from these alkynyl sulfide ring closures are believed to be formed under kinetic control.The methodology has been applied to the synthesis of unusual bicyclic β-lactams related to the penicillin family of antibiotics.
Intramolecular N-(Acyloxy)iminium Ion-Alkyne Cycloadditions. A New Route to Bicyclic α-Amino Ketones
Fisher, Matthew J.,Overman, Larry E.
, p. 1447 - 1459 (2007/10/02)
The intramolecular cyclocondensation of 15 cyclic N-(acyloxy)iminium cations containing tethered alkyne and alkene nucleophiles is reported (eqs 5 and 6).This route to heterotricyclic systems was specifically demonstrated with substrates in which the hete
