49642-49-1Relevant articles and documents
Enantiopure Acetals of α-Alkynyl Carbonyl Compounds: Organoaluminum-Mediated 1,2-Shift of Cobalt-Complexed Alkynyl Group with Concomitant Capture by a Nucleophile
Taya, Kimiko,Nagasawa, Tetsuya,Suzuki, Keisuke
, p. 304 - 306 (1997)
Upon treatment with the organoaluminum-based combination of Lewis acid and nucleophile, chiral mesyloxy acetal having a Co-complexed alkynyl group undergoes stereospecific 1,2-shift of the complexed alkynyl and the concomitant attack of the ligand R of the organoaluminum reagent. Decomplexation of the products with CAN gives the chiral acetals of α-alkynyl carbonyl compounds in enantiomerically pure form in high yields.
Chemo- And regioselective hydroformylation of alkenes with CO2/H2over a bifunctional catalyst
Hua, Kaimin,Liu, Xiaofang,Wei, Baiyin,Shao, Zilong,Deng, Yuchao,Zhong, Liangshu,Wang, Hui,Sun, Yuhan
supporting information, p. 8040 - 8046 (2021/11/01)
As is well known, CO2 is an attractive renewable C1 resource and H2 is a cheap and clean reductant. Combining CO2 and H2 to prepare building blocks for high-value-added products is an attractive yet challenging topic in green chemistry. A general and selective rhodium-catalyzed hydroformylation of alkenes using CO2/H2 as a syngas surrogate is described here. With this protocol, the desired aldehydes can be obtained in up to 97% yield with 93/7 regioselectivity under mild reaction conditions (25 bar and 80 °C). The key to success is the use of a bifunctional Rh/PTA catalyst (PTA: 1,3,5-triaza-7-phosphaadamantane), which facilitates both CO2 hydrogenation and hydroformylation. Notably, monodentate PTA exhibited better activity and regioselectivity than common bidentate ligands, which might be ascribed to its built-in basic site and tris-chelated mode. Mechanistic studies indicate that the transformation proceeds through cascade steps, involving free HCOOH production through CO2 hydrogenation, fast release of CO, and rhodium-catalyzed conventional hydroformylation. Moreover, the unconventional hydroformylation pathway, in which HCOOAc acts as a direct C1 source, has also been proved to be feasible with superior regioselectivity to that of the CO pathway.
Methyl-modified cage-type phosphorus ligand and preparation method thereof Preparation method and application thereof
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Paragraph 0075-0084; 0087-0088, (2021/09/15)
The invention discloses a methyl-modified cage-type phosphorus ligand, a preparation method and application thereof, in particular to a synthesis design, wherein methyl is further introduced on a phenyl ring of triphenylphosphine, and a methyl-modified cage-type phosphorus ligand is synthesized, and when a methyl meta-substituted cage-type phosphorus ligand is used as a hydroformylation reaction catalyst the proportion of n-structural aldehyde and isomeric aldehyde is 2.6. TOF-1 The methyl-substituted cage-type phosphorus ligand is excellent in performance, stable in property and recyclable, has excellent substrate applicability in the hydroformylation catalytic reaction, has a good industrial application prospect, and has very important significance in metal organic catalysis.