Advanced Synthesis and Catalysis p. 4132 - 4141 (2018)
Update date:2022-08-03
Topics:
Di Carmine, Graziano
Bortolini, Olga
Massi, Alessandro
Müller, Michael
Bernacchia, Giovanni
Fantin, Giancarlo
Ragno, Daniele
Giovannini, Pier Paolo
Benzoin-type reactions have been intensively exploited as a synthetic strategy for the preparation of α-hydroxy ketones. Thiamine diphosphate (ThDP) dependent enzymes are excellent catalysts for asymmetric versions of such reaction types. In particular, in cross-benzoin condensations of aromatic reactants and mixed aromatic/aliphatic reactions, use of these enzymes has resulted in high levels of chemo-, regio- and stereoselectivity. The present work, which confirms this trend for aliphatic reactants, outlines results obtained in the formal cross-benzoin-type condensation of the ‘umpoled’ acetaldehyde and propionaldehyde with various aliphatic aldehydes catalyzed by the ThDP-dependent enzyme acetoin:dichlorophenolindophenol oxidoreductase (Ao:DCPIP OR). In these reactions, 3-hydroxy-3-methylbutan-2-one (methylacetoin) was used as the activated acetaldehyde donor, while 4-hydroxy-4-methylhexan-3-one was employed for the first time as the precursor of activated propionaldehyde. With the exception of 3-hydroxypentan-2-one and 3-hydroxyhexan-2-one, which were obtained in almost racemic form by the condensation of methylacetoin with propanal and butanal, respectively, all other products achieved from reactions performed using the same donor with more hindered aldehyde acceptors were obtained with high conversions (89–99%) and in good to high enantiomeric excess (72–99% ee). In a similar way, high conversions (75–99%) and good ee (76–99%) were observed in reactions performed with the same set of aldehyde acceptors, but using 4-hydroxy-4-methylhexan-3-one as propionyl anion donor. This is the first time that most of the products described herein have been prepared via benzoin-type condensation. (Figure presented.).
View MoreShanghai Xinda Pharmaceuticals Co., Ltd.
Contact:86-21-33692333-8008
Address:999 Linxian Road, Jinshan Industrial Park, Shanghai, China
Shanghai He Yang International Trading Co., Ltd.
Contact:+86-21-52043598
Address:Room 816, Blag.5, No.58 Huachi Road
Shanghai Hongbang Medical Technology CO.,. Ltd
Contact:13671516988 /18917636693
Address:Room1, No67 Building, Yongde Road369, Wujing Town, Minhang Districy, Shanghai CIty, China.
Contact:+86 21 5017 5386
Address:No 999,Jiangyue Rd, Minhang Dist ,201114,Shanghai ,China
website:http://www.cheminn.com/
Contact:86-531-67875205
Address:No.9-2,South of Shanda Road, Jinan ,China
Doi:10.1016/S0277-5387(00)86523-7
(1989)Doi:10.1002/hlca.200900364
(2010)Doi:10.1016/0022-328X(89)87349-8
(1989)Doi:10.1016/S0040-4039(01)93417-3
(1989)Doi:10.1134/S1070428010020144
(2010)Doi:10.1134/S1070428009050030
(2009)