16452-34-9Relevant academic research and scientific papers
Enantioselective Radical Construction of 5-Membered Cyclic Sulfonamides by Metalloradical C-H Amination
Hu, Yang,Lang, Kai,Li, Chaoqun,Gill, Joseph B.,Kim, Isaac,Lu, Hongjian,Fields, Kimberly B.,Marshall, McKenzie,Cheng, Qigan,Cui, Xin,Wojtas, Lukasz,Zhang, X. Peter
supporting information, p. 18160 - 18169 (2019/11/19)
Both arylsulfonyl and alkylsulfonyl azides can be effectively activated by the cobalt(II) complexes of D2-symmetric chiral amidoporphyrins for enantioselective radical 1,5-C-H amination to stereoselectively construct 5-membered cyclic sulfonami
Pyrrolidines and Piperidines by Ligand-Enabled Aza-Heck Cyclizations and Cascades of N-(Pentafluorobenzoyloxy)carbamates
Hazelden, Ian R.,Carmona, Rafaela C.,Langer, Thomas,Pringle, Paul G.,Bower, John F.
, p. 5124 - 5128 (2018/03/26)
Ligand-enabled aza-Heck cyclizations and cascades of N-(pentafluorobenzoyloxy)carbamates are described. These studies encompass the first examples of efficient non-biased 6-exo aza-Heck cyclizations. The methodology provides direct and flexible access to carbamate protected pyrrolidines and piperidines.
Diverse N-Heterocyclic Ring Systems via Aza-Heck Cyclizations of N-(Pentafluorobenzoyloxy)sulfonamides
Hazelden, Ian R.,Ma, Xiaofeng,Langer, Thomas,Bower, John F.
, p. 11198 - 11202 (2016/10/13)
Aza-Heck cyclizations initiated by oxidative addition of Pd0-catalysts into the N?O bond of N-(pentafluoro-benzoyloxy)sulfonamides are described. These studies, which encompass only the second class of aza-Heck reaction developed to date, provide direct access to diverse N-heterocyclic ring systems.
Low-valent titanium-mediated stereoselective alkylation of allylic alcohols
Lysenko, Ivan L.,Kim, Keunho,Hyung, Goo Lee,Jin, Kun Cha
body text, p. 15997 - 16002 (2009/05/15)
We have developed low-valent titanium-mediated 1,3-transpositive cross-coupling reactions of acyclic and cyclic allylic alcohols for the stereoselective introduction of ethyl, 2-silylethyl, 2-phenethyl, and alkenyl groups. Cross-coupling of an allylic alcohol with a vinylsilane or styrene derivative is particularly noteworthy, as an efficient cross-selective coupling of two alkenes has been elusive. The stereochemistry of the cross-coupling alkylation is consistent with syn addition/β-elimination.
Oxidative cyclizations in a nonpolar solvent using molecular oxygen and studies on the stereochemistry of oxypalladation
Trend, Raissa M.,Ramtohul, Yeeman K.,Stoltz, Brian M.
, p. 17778 - 17788 (2007/10/03)
Oxidative cyclizations of a variety of heteroatom nucleophiles onto unactivated olefins are catalyzed by palladium(II) and pyridine in the presence of molecular oxygen as the sole stoichiometric oxidant in a nonpolar solvent (toluene). Reactivity studies of a number of N-ligated palladium complexes show that chelating ligands slow the reaction. Nearly identical conditions are applicable to five different types of nucleophiles: phenols, primary alcohols, carboxylic acids, a vinylogous acid, and amides. Electronrich phenols are excellent substrates, and multiple olefin substitution patterns are tolerated. Primary alcohols undergo oxidative cyclization without significant oxidation to the aldehyde, a fact that illustrates the range of reactivity available from various Pd(II) salts under differing conditions. Alcohols can form both fused and spirocyclic ring systems, depending on the position of the olefin relative to the tethered alcohol; the same is true of the acid derivatives. The racemic conditions served as a platform for the development of an enantioselective reaction. Experiments with stereospecifically deuterated primary alcohol substrates rule out a "Wacker-type" mechanism involving anti oxypalladation and suggest that the reaction proceeds by syn oxypalladation for both mono- and bidentate ligands. In contrast, cyclizations of deuterium-labeled carboxylic acid substrates undergo anti oxypalladation.
Palladium(II)-catalyzed cyclization using molecular oxygen as reoxidant
Roenn, Magnus,Baeckvall, Jan-E.,Andersson, Pher G.
, p. 7749 - 7752 (2007/10/02)
A palladium(II)-catalyzed intramolecular allylic oxidations using, nitrogen and oxygen nucleophiles and molecular oxygen as reoxidant has been developed.
ALIPHATIC CLAISEN REARRANGEMENT PROMOTED BY ORGANOALUMINIUM COMPOUNDS
Takai, Kazuhiko,Mori, Ichiro,Oshima, Koichiro,Nozaki, Hitosi
, p. 3985 - 3988 (2007/10/02)
Treatment of allyl vinyl ether derivatives with organoaluminium amphoteric reagent, R3Al or R2AlSPh, results in the title reaction at room temperature under uptake of R, H, or SPh as a nucleophile on the aldehydic carbon.
