iron-catalyzed selective reduction of CO2 into formaldehyde via formation and controlled hydrolysis of a bis(boryl)acetal compound. The second step concerns the carbene-catalyzed C–C bond formation to afford glycolaldehyde. Both carbon atoms of glycolaldehyde arise from CO2 as proven by the labeling experiment with 13CO2. This hybrid organometallic/organic catalytic system employs mild conditions (1 atm of CO2
以甲醛为主要中间体,通过一锅两步法将CO 2选择性二聚为乙醇醛。第一步涉及通过双(硼基)乙缩醛化合物的形成和受控水解,铁催化将CO 2选择性还原为甲醛。第二步涉及形成卡宾催化的CC键以生成乙醇醛。乙醇醛的两个碳原子均由CO 2产生,正如13 CO 2的标记实验所证明的。这种混合的有机金属/有机催化系统采用温和的条件(1个大气压的CO 2,在不到3小时的时间内达到25至80°C)和低催化负荷(分别为1%和2.5%)。乙醇醛的总产率为53%。乙醇醛具有吸引力的反应性示例为(i)在导致C 4醛糖化合物的二聚化过程中,以及(ii)在一个过程中生成C–N和C–C键的三组分Petasis–Borono–Mannich反应中。
Systematic Studies on the Chemical Structure and Umami Enhancing Activity of Maillard-Modified Guanosine 5′-Monophosphates
作者:Daniel Festring、Thomas Hofmann
DOI:10.1021/jf103849e
日期:2011.1.26
the discovery of (R)- and (S)-N2-(1-carboxyethyl)-guanosine 5′-monophosphate as previously not reported umami enhancing molecules formed upon the Maillard reaction of guanosine5′-monophosphate (5′-GMP) with dihydroxyacetone and glyceraldehyde, respectively. In the present study, systematic Maillard-type model reactions were performed with 5′-GMP and a homologous series of monosaccharides exhibiting
Tertiary Amine Promoted Asymmetric Aldol Reaction of Aldehydes
作者:Bartosz Gut、Jacek Mlynarski
DOI:10.1002/ejoc.201500519
日期:2015.8
direct asymmetric self-aldol reactions of various α-oxyaldehydes catalyzed by tertiaryamines have been demonstrated. By using 10 mol-% of quinine catalyst, dimerization products have been prepared in high yields, with good anti-diastereocontrol, and up to 80 % ee. The presented enolate-mediated synthesis of protected tetrose sugars has never been accomplished before by chiral tertiaryamine organocatalysts
Deuterium Studies Reveal a New Mechanism for the Formose Reaction Involving Hydride Shifts
作者:Chandrakumar Appayee、Ronald Breslow
DOI:10.1021/ja410886c
日期:2014.3.12
In the formose reaction, formaldehyde is converted to glycolaldehyde, its dimer, under credible prebiotic conditions. Breslow proposed a mechanism for the process in 1959, but recent studies by Benner showed that it was wrong in detail. Our present studies clarify the mechanism, which involves the original Breslow intermediates but some different connecting steps.
A plausible prebiotic selection of ribose for RNA - formation, dynamic isolation, and nucleotide synthesis based on metal-doped-clays
作者:Ze-Run Zhao、Xiao Wang
DOI:10.1016/j.chempr.2021.09.002
日期:2021.12
selectively bind to ribose against other monosaccharides. Excitingly, ribose can be continuously and highly selectively enriched on metal-doped-clays (MDCs) from a complex Formose mixture, which could be the origin of its rise to prominence. Prebiotic scenarios of the dynamic isolation of ribose from sugar mixture are simulated with microflow technology. The MDC-retained ribose exhibits long-term stability