110773-62-1Relevant articles and documents
Accessible protocol for asymmetric hydroformylation of vinylarenes using formaldehyde
Morimoto, Tsumoru,Fujii, Tetsuji,Miyoshi, Kota,Makado, Gouki,Tanimoto, Hiroki,Nishiyama, Yasuhiro,Kakiuchi, Kiyomi
supporting information, p. 4632 - 4636 (2015/04/27)
We report herein on an accessible protocol for the asymmetric hydroformylation of vinylarenes using formaldehyde as a substitute for syngas. The regioselectivity (branched/linear = up to 96/4) and enantioselectivity (up to 95% ee) can be attributed to the use of chiral Ph-bpe as a ligand. This journal is
Exploring the synthetic applicability of a new carboxylic acid reductase from Segniliparus rotundus DSM 44985
Duan, Yitao,Yao, Peiyuan,Chen, Xi,Liu, Xiangtao,Zhang, Rui,Feng, Jinhui,Wu, Qiaqing,Zhu, Dunming
, p. 1 - 7 (2015/02/19)
A new carboxylic acid reductase (CAR) gene from Segniliparus rotundus DSM 44985 was overexpressed in Escherichia coli. The recombinant enzyme exhibited high activity toward a variety of aromatic and aliphatic carboxylic acids. Especially, it effectively reduced 4-hydroxybenzoic acid (8a) and 4-nitrobenzoic acid (19a), toward which the known Nocardia CAR exhibited no or little activity. The recombinant E. coli cells co-expressing the Segniliparus CAR and Nocardia PPTase genes catalyzed the reductions of vanillic acid (20a) and 3,4-dihydroxyphenylacetic acid (25a) to give vanillyl alcohol (20c) and 3-hydroxytyrosol (25c) with high yield, respectively. The endogenous aldehyde reductases of E. coli should be responsible for the further reduction of the produced aldehydes. These results demonstrated that Segniliparus CAR was a useful addition to the biocatalyst tool-box for the reduction of carboxylic acids and might find applications in the synthesis of valuable bio-based chemicals from renewable resources.
Highly efficient enantioselective catalysis in supercritical carbon dioxide using the perfluoroalkyl-substituted ligand (R,S)-3-H2F6-BINAPHOS
Franciò, Giancarlo,Wittmann, Klaus,Leitner, Walter
, p. 130 - 142 (2007/10/03)
Perfluoroalkyl-substitution of the aryl groups in the BINAPHOS skeleton was achieved using a synthetic strategy based on the Cu(I)-catalyzed cross coupling of arylmagnesium bromide and F(CF2)6(CH2)2I. The rhodium complexes of the new ligand (R,S)-3-H2F6-BINAPHOS (10) exhibited spectroscopic properties and reactivities similar to those of the unsubstituted parent compounds. The substitution provided a high affinity of the ligand and its complexes for scCO2 allowing the development of ecologically benign protocols for catalytic asymmetric synthesis and even the spectroscopic detection of catalytically active intermediates. Using this new system, a large variety of substrates were hydroformylated in scCO2 with rates and enantioselectivities comparable to those of the parent system in benzene solution. At the same time, the CO2-philic substitution pattern resulted in a significantly higher regioselectivity towards the desired chiral aldehydes. Preliminary results indicated for the first time also a remarkable potential of BINAPHOS-derived ligands for asymmetric hydrogenation reactions. The possibility to develop new work-up schemes for product purification and/or catalyst immobilisation based on scCO2 as the only medium for catalysis and extraction (CESS process) was experimentally verified using a rhodium catalyst containing 10.
