188026-80-4Relevant academic research and scientific papers
Pinacol Cross Coupling Reactions of Ethyl 2-Alkyl-2-Formylpropionates. Stereoselective Synthesis of 2,2,4-Trialkyl-3-Hydroxy-γ-Butyrolactones
Kang, Min,Park, Jeonghan,Pedersen, Steven F.
, p. 41 - 43 (1997)
Intermolecular pinacol coupling of ethyl 2-alkyl-2-formylpropionates (2) (i.e. EtOC(O)CR1MeCHO) with non-chelating aldehydes provides high yields of threo diols. The reaction is promoted by vanadium(II) ions which are conveniently generated in situ from VCl3(THF)3 and zinc dust. High diastereofacial selectivity is observed when starting with chiral 2, or chiral non-chelating aldehydes.
Rhodium-Catalyzed Enantioselective Anti-Markovnikov Hydroformylation of α-Substituted Acryl Acid Derivatives
Li, Shuailong,Li, Zhuangxing,You, Cai,Li, Xiuxiu,Yang, Jiaxin,Lv, Hui,Zhang, Xumu
supporting information, p. 1108 - 1112 (2020/02/04)
Rhodium-catalyzed asymmetric anti-Markovnikov hydroformylation of α-substituted acrylates/acrylamides has been developed. By employing the Rh/(S,S)-DTBM-YanPhos complex, a series of β-chiral linear aldehydes were obtained in high yields (up to 94% yield) and high enantioselectivities (up to 96% ee). The utility of this methodology is demonstrated by a gram-scale reaction and a concise synthetic route to chiral ?3-butyrolactone.
Exploiting Carbonyl Groups to Control Intermolecular Rhodium-Catalyzed Alkene and Alkyne Hydroacylation
Coxon, Thomas J.,Fernández, Maitane,Barwick-Silk, James,McKay, Alasdair I.,Britton, Louisa E.,Weller, Andrew S.,Willis, Michael C.
supporting information, p. 10142 - 10149 (2017/08/02)
Readily available β-carbonyl-substituted aldehydes are shown to be exceptional substrates for Rh-catalyzed intermolecular alkene and alkyne hydroacylation reactions. By using cationic rhodium catalysts incorporating bisphosphine ligands, efficient and selective reactions are achieved for β-amido, β-ester, and β-keto aldehyde substrates, providing a range of synthetically useful 1,3-dicarbonyl products in excellent yields. A correspondingly broad selection of alkenes and alkynes can be employed. For alkyne substrates, the use of a catalyst incorporating the Ampaphos ligand triggers a regioselectivity switch, allowing both linear and branched isomers to be prepared with high selectivity in an efficient manner. Structural data, confirming aldehyde chelation, and a proposed mechanism are provided.
Rh-catalyzed asymmetric hydroformylation of functionalized 1,1-disubstituted olefins
Wang, Xiao,Buchwald, Stephen L.
supporting information; scheme or table, p. 19080 - 19083 (2012/01/05)
The first method for the highly enantioselective rhodium-catalyzed hydroformylation of 1,1-disubstituted olefins has been developed. By employing either of the P-chirogenic phosphine ligands BenzP* and QuinoxP*, linear aldehydes with β-chirality can be prepared in a highly enantioselective fashion with good chemo- and regioselectivities.
