Tandem Hydroformylation/Acyloin Reaction - The Synergy of Metal Catalysis and Organocatalysis Yielding Acyloins Directly from Olefins
作者:Karoline A. Ostrowski、Thiemo A. Faßbach、Andreas J. Vorholt
DOI:10.1002/adsc.201401031
日期:2015.5.4
A novel, atom efficient, orthogonal tandem catalysis was developed yielding acyloin products (α‐hydroxy ketones) directly from olefins under hydroformylation conditions. The combination of a metal‐catalysed hydroformylation and an organocatalysed acyloin reaction provides three atom efficient CC bond formations to linear, multifunctional molecules via linkage of the intermediate n‐aldehydes. Additionally
Boronic Acid-Catalyzed Selective Oxidation of 1,2-Diols to α-Hydroxy Ketones in Water
作者:Julius M. William、Masami Kuriyama、Osamu Onomura
DOI:10.1002/adsc.201300961
日期:2014.3.24
2‐diols to their corresponding α‐hydroxy ketones in aqueous medium. The oxidation step was accomplished using dibromoisocyanuricacid (DBI) as a terminal chemical oxidant or an electrochemical process. The electrochemical process was based on the use of platinum electrodes, methylboronic acid [MeB(OH)2] as a catalyst and bromide ion as a mediator. Electro‐generated OH− ions (EGB) at the cathode acted
The present invention relates to a new process for the generation of pyrazines consisting in the bioconversion of hydroxyketones with 1,2-diaminopropane. New tetrahydropyrazine derivatives as well as new dihydropyrazine derivatives with high flavour and low threshold properties are disclosed. Such pyrazines compounds exhibiting roasted and earthy aroma profiles may be used in the food and bevererage industry, especially chocolate, confectionery and coffee.
The aerobic oxidation of α-hydroxy ketones into α-diketones catalyzed by CaO is compared with the same reaction catalyzed by other metal oxides. The catalytic activities of the various metal oxides were proportional to their surface basicities. The direct conversion of α-hydroxy ketones into quinoxalines via CaO-catalyzed aerobic oxidation followed by in situ reaction with 1,2-diaminoaromatics is also achieved. Various types of quinoxalines were synthesized in the presence of the CaO catalyst and molecular oxygen. It was also found that the CaO catalyst was reusable without any loss of its catalytic activity.
Simple method for selective oxidation of 1,2-diols in water with KBrO3/KHSO4
作者:Julius M. William、Masami Kuriyama、Osamu Onomura
DOI:10.1016/j.tetlet.2014.10.035
日期:2014.11
Readily available off-the-shelf KBrO3 and KHSO4 have been used to selectively oxidize 1,2-diols in water as a solvent. Various cyclic 1,2-diols have been tolerated affording their corresponding α-hydroxy ketones in good yields.