155619-05-9Relevant articles and documents
Binuclear Pd(I)-Pd(I) Catalysis Assisted by Iodide Ligands for Selective Hydroformylation of Alkenes and Alkynes
Zhang, Yang,Torker, Sebastian,Sigrist, Michel,Bregovi?, Nikola,Dydio, Pawe?
supporting information, p. 18251 - 18265 (2020/11/02)
Since its discovery in 1938, hydroformylation has been thoroughly investigated and broadly applied in industry (>107 metric ton yearly). However, the ability to precisely control its regioselectivity with well-established Rh- or Co-catalysts has thus far proven elusive, thereby limiting access to many synthetically valuable aldehydes. Pd-catalysts represent an appealing alternative, yet their use remains sparse due to undesired side-processes. Here, we report a highly selective and exceptionally active catalyst system that is driven by a novel activation strategy and features a unique Pd(I)-Pd(I) mechanism, involving an iodide-assisted binuclear step to release the product. This method enables β-selective hydroformylation of a large range of alkenes and alkynes, including sensitive starting materials. Its utility is demonstrated in the synthesis of antiobesity drug Rimonabant and anti-HIV agent PNU-32945. In a broader context, the new mechanistic understanding enables the development of other carbonylation reactions of high importance to chemical industry.
Dual Catalysis Using Boronic Acid and Chiral Amine: Acyclic Quaternary Carbons via Enantioselective Alkylation of Branched Aldehydes with Allylic Alcohols
Mo, Xiaobin,Hall, Dennis G.
, p. 10762 - 10765 (2016/09/09)
A ferrocenium boronic acid salt activates allylic alcohols to generate transient carbocations that react with in situ-generated chiral enamines from branched aldehydes. The optimized conditions afford the desired acyclic products embedding a methyl-aryl quaternary carbon center with up to 90% yield and 97:3 enantiomeric ratio, with only water as the byproduct. This noble-metal-free method complements alternative methods that are incompatible with carbon-halogen bonds and other sensitive functional groups.
Acetolysis of 2-Aryl-1-methylpropyl Systems: Mechanism of the Formation of the Retained Product without Neighbouring Group Participation
Kinoshita, Tomomi,Takemoto, Masaki,Shibayama, Koichi,Takeuchi, Ken'ichi
, p. 2153 - 2174 (2007/10/02)
threo-2--1-(13C)methylpropyl p-bromobenzenesulphonate (threo-(13C)1-OBs) has been solvolyzed in acetic acid to give rise to the retained threo-1-OAc which contains a small amount of threo-(13C)1-OAc accompanying no 13C-scrambling.At 75percent conversion, the isomerized erythro-1-OBs has been obtained along with the unchanged threo-1-OBs.Also, the erythro-1-OTs has been found at 50percent conversion in the presence of NaOTs.These stereochemical results indicate strongly that the acetate with the retained configuration accompanying no 13C-scrambling is formed via isomerization of the substrate by inversive anion exchange and a successive ks pathway with configurational inversion.Such a retained product was not detected in the acetolysis of threo-1-methyl-2-phenylpropyltoluene-p-sulphonate with no electron withdrawing substituent.
