6838-54-6Relevant articles and documents
Steric Influence on Reactions of Benzyl Potassium Species with CO
Wang, Tongtong,Xu, Maotong,Jupp, Andrew R.,Qu, Zheng-Wang,Grimme, Stefan,Stephan, Douglas W.
supporting information, p. 3640 - 3644 (2021/10/19)
Reactions of benzyl potassium species with CO are shown to proceed via transient carbene-like intermediates that can undergo either dimerization or further CO propagation. In a sterically unhindered case, formal dimerization of the carbene is the dominant reaction pathway, as evidenced by the isolation of ((Ph3SiO)(PhCH2)C)2 2 and PhCH2C(O)CH(OH)CH2Ph 3. Reactions with increasingly sterically encumbered reagents show competitive reaction pathways involving intermolecular dimerization leading to species analogous to 2 and 3 and those containing newly-formed five-membered rings tBu2C6H2(C(OSiR3)C(OSiR3)CH2) (R=Me 6, Ph 7). Even further encumbered reagents proceed to either dimerize or react with additional CO to give a ketene-like intermediates, thus affording a 7-membered tropolone derivative 14 or the dione (3,5-tBu2C6H3)3C6H2CH2C(O))2 15.
Synthesis of maculalactone A and derivatives for environmental fate tracking studies
Bader, Samuel L.,Luescher, Michael U.,Gademann, Karl
, p. 199 - 206 (2015/02/19)
Maculalactone A (1) constitutes a promising antifouling agent, inhibiting the formation of biofilms in marine and freshwater systems. In this study, we developed a new route, based on a late-stage formation of the butenolide core, leading to the total synthesis of maculalactone A (three steps, overall yield of 45%) and delivering material on a gram scale. In addition, analogues of the title compound were assayed concerning their biological activity, utilizing Artemia franciscana and Thamnocephalus platyurus. The most active analogue was functionalized with a rhodamine B fluorophore and was utilized in an in vivo staining experiment in Artemia salina. Two different tissues were found to accumulate this maculalactone A derivative. This journal is
Asymmetric acyloin condensation catalysed by phenylpyruvate decarboxylase. Part 2: Substrate specificity and purification of the enzyme
Guo, Zhiwei,Goswami, Animesh,Nanduri, Venkata B.,Patel, Ramesh N.
, p. 571 - 577 (2007/10/03)
Phenylpyruvate decarboxylase from Achromobacter eurydice was used to catalyse the asymmetric acyloin condensation of phenylpyruvate 1 with various aldehydes 2 to produce optically active acyloins PhCH2COCH(OH)R 3. The specific activity of the phenylpyruvate decarboxylase enzyme was increased by a factor of 332 after its purification. The molecular weight of the purified enzyme was shown to be 150 kDa by gel filtration chromatography, while SDS gel electrophoresis showed two sub-units with molecular weights of 90 and 40 kDa. The acyloin condensation yield decreased with increasing chain length for straight chain aliphatic aldehydes from 76% for acetaldehyde to 24% for valeraldehyde. The e.e.s of the acyloin products were 87-98%. Low yields of acyloin products were obtained with chloroacetaldehyde (13%) and glycoaldehyde (16%). Indole-3-pyruvate was a substrate of the enzyme and provided acyloin condensation product 3-hydroxy-1-(3-indolyl)-2-butanone 5 with acetaldehyde in 19% yield, while benzoylformate was not a substrate for the enzyme.
