An expedient synthesis of 2,4,5-trisubstituted 1,4-pentadienes from Baylis–Hillman adducts via the Pd-catalyzed decarboxylation–elimination protocol
摘要:
We disclosed an efficient synthetic method of 2,4,5-trisubstituted 1,4-pentadienes from Baylis-Hillman adducts via the Pd-catalyzed decarboxylation-elimination protocol as the key step. (C) 2009 Elsevier Ltd. All rights reserved.
Bioreduction of α-Acetoxymethyl Enones: Proposal for an S<sub>N</sub>2′ Mechanism Catalyzed by Enereductase
作者:Bruno R. S. Paula、Davila Zampieri、J. Augusto R. Rodrigues、Paulo J. S. Moran
DOI:10.1002/adsc.201600601
日期:2016.11.17
acylated Morita–Baylis–Hillman adduct 1‐acetoxy‐2‐methylene‐1‐phenylbutan‐3‐one produced a mixture of products, with and without the acetoxygroup, via three different reaction pathways. In addition to experiments employing whole cells, those in which isolated enereductases were used suggested that the main pathway through which the loss of the acetoxygroup occurs during the biocatalytic cascade is an SN2′‐type
(Z)-3-乙酰氧基甲基-4-R-3-丁烯-2-酮(R =芳基,烷基)和(Z)-3-甲基-4-R-3-丁烯-2-丁烯(R =芳基)合成并通过酿酒酵母进行还原,分别产生(R)-和(S)-4-R-3甲基丁烷-2-。这种立体化学控制策略适用于对映体过量至中度过量的(R)-和(S)-Tropional®的合成。其他(Z)-3-酰氧基甲基-4-苯基-3-丁烯-2-酮的行为与(Z)-3-乙酰氧基甲基对应物和酰化的Morita-Baylis-Hillman加合物1-乙酰氧基-2-亚甲基-1-苯基丁烷-3-酮通过三种不同的反应途径生成了带有或不带有乙酰氧基的产物混合物。除了使用全细胞的实验外,使用分离的烯还原酶的实验还表明,在生物催化级联反应中发生乙酰氧基丢失的主要途径是S N 2'型反应,而不是正式的氢加成反应。消除乙酸。最后,相关的乙基烯酮被酵母白色念珠菌对映体选择性还原,产生(R)-和(S)还原产物,取决于起始原料中乙酰氧基的存在。
Enantiodivergence in the reduction of α-methyl and α-halomethyl enones by microorganisms
作者:Bruno R.S. de Paula、Dávila S. Zampieri、J. Augusto R. Rodrigues、Paulo J.S. Moran
DOI:10.1016/j.tetasy.2013.07.007
日期:2013.9
Enones (Z)-3-methyl-(Z)-3-chloromethyl- and (Z)-3-bromomethyl-4-R-3-buten-2-one (R = n-pentyl, phenyl, 2'- and 4'-chlorophenyl, 3'- and 4'-nitrophenyl, 4'-methoxyphenyl) were synthesized and subjected to reduction by the microorganisms Saccharomyces cerevisiae and Geotrichum candidum. Whereas the bioreduction of 3-methy-4-R-3-buten-2-ones afforded the corresponding (S)-4-R-3-methybutan-2-ones, the bioreduction of 3-chloromethyl- and 3-bromomethyl-4-R-3-buten-2-ones afforded the corresponding (R)-4-R-3-methybutan-2-ones. (C) 2013 Elsevier Ltd. All rights reserved.
Copper-Catalyzed Asymmetric 1,2-Addition of Grignard Reagents to 3-Acyl 2H-chromenes
作者:Adriaan Minnaard、Beatriz Calvo
DOI:10.1055/s-0036-1588532
日期:2017.12
Enones in which the carbon–carbon double bond is part of the pharmacologically important 2 H -chromene (2 H -1-benzopyran) nucleus undergo asymmetric copper-catalyzed 1,2-addition of Grignardreagents. High yields and enantiomeric excesses up to 84% are obtained and access to these novel enantio-enriched tertiary alcohols is provided.
其中碳 - 碳双键是药理学上重要的 2 H -色烯(2 H -1-苯并吡喃)核的一部分的烯酮经历不对称铜催化的格氏试剂的 1,2-加成。获得了高达 84% 的高产率和对映体过量,并提供了获得这些新型对映体富集的叔醇的途径。
An expedient synthesis of 2,4,5-trisubstituted 1,4-pentadienes from Baylis–Hillman adducts via the Pd-catalyzed decarboxylation–elimination protocol
作者:Ko Hoon Kim、Eun Sun Kim、Jae Nyoung Kim
DOI:10.1016/j.tetlet.2009.06.142
日期:2009.9
We disclosed an efficient synthetic method of 2,4,5-trisubstituted 1,4-pentadienes from Baylis-Hillman adducts via the Pd-catalyzed decarboxylation-elimination protocol as the key step. (C) 2009 Elsevier Ltd. All rights reserved.