3212-15-5Relevant articles and documents
Photoinduced Fragmentation Borylation of Cyclic Alcohols and Hemiacetals
Aggarwal, Varinder K.,Madhavachary, Rudrakshula,Noble, Adam,Shu, Chao
supporting information, p. 7213 - 7218 (2020/10/12)
A visible-light photoinduced fragmentation borylation of O-phthalimido cycloalkanols with bis(catecholato)diboron is described. Structurally diverse keto and formyloxy alkyl boronic esters are shown to be conveniently prepared by radical-mediated ring opening of cyclic alcohols and hemiacetals, respectively. The reactions proceed under mild conditions in the absence of additives or photocatalysts, display excellent functional group tolerance, and are shown to allow cleavage of 4-, 5-, 6-, and 7-membered ring substrates. The mechanism proceeds via sequential homolytic N-O and C-C bond cleavages, the latter of which involves β-scission of an alkoxy radical, generating a carbonyl and an alkyl radical that is trapped by the diboron reagent. Spectroscopic studies suggest direct photoexcitation of either the phthalimide or diboron substrates with blue light can initiate a radical chain mechanism.
RUTHENIUM-CATALYZED C-H BOND ACTIVATION OXIDATION OF BRIDGED BICYCLIC AND TRICYCLIC ALKANES
Tenaglia, A.,Terranova, E.,Waegell, B.
, p. 5271 - 5274 (2007/10/02)
Catalytic oxydation (hydroxylation) with RuO4 generated in situ occurs preferentially in tertiary position with retention of configuration on various bicyclic or tricyclic alcanes.
Large Intrinsic Nuclear Magnetic Resonance Isotope Shifts Associated with Bending Motion along the Bridging Coordinate in Carbocations
Forsyth, David A.,Botkin, James H.,Puckace, James S.,Servis, Kenneth L.,Domenick, Robert L.
, p. 7270 - 7276 (2007/10/02)
Deuterium isotope effects on the 13C NMR chemical shifts have been determined for the 2-methyl-2-bicyclooctyl and 2-methyl-2-bicycloheptyl cations.These tertiary carbocations have isotope shifts that are larger than 1 ppm per deuterium, which is an order of magnitude larger than ordinary intrinsic shifts found in nonionic model compounds and in other carbocations.For deuteriation at C3 methylene or methyl group, the same pattern occurs in both cations: isotope shifts that are large and upfield at C2, downfield at C1, and upfield at the remaining carbon directly bonded to C2.The similarity in the pattern of the isotope shifts suggests that the force field and shielding influences in both ions are similar.The specific results are interpreted as indicating the presence of a shallow potential surface for the bending motion along the direction associated with ?-bridging.Since the existence of the shallow potential does not depend on the actual extent of bridging, the magnitude of the isotope effect is not proportional to the extent of bridging.