Metal-Free Oxidative Ipso-Carboacylation of Alkynes: Synthesis of 3-Acylspiro[4,5]trienones from N-Arylpropiolamides and Aldehydes
摘要:
A general and metal-free radical route to synthesis of 3-acylspiro[4,5]trienones is established that utilizes TBHP (tert-butyl hydrogenperwdde) as an oxidation and a reaction partner to trigger the oxidative ipso-carboacylation of N-arylpropiolamides with aldehydes. This method offers a new difunctionalization of alkynes through oxidative cross coupling of the aldehyde C(sp(2))-H bond with an ipso-aromatic carbon.
peptide synthesis (SPPS). The robustness of the allenone-mediated peptide bond formation was showcased incisively by the synthesis of carfilzomib, which involved a rare racemization-/epimerization-free N to C peptide elongation strategy. Furthermore, the successful synthesis of the model difficult peptide ACP (65–74) on a solid support suggested that this method was compatible with SPPS. This method combines
Allenone 首次被鉴定为一种高效的肽偶联剂。肽键以α-羰基乙烯基酯为关键中间体形成,其形成和随后的氨解以无外消旋/差向异构化的方式自发进行。丙二烯酮偶联试剂不仅对简单酰胺和二肽的合成有效,而且还适用于肽片段缩合和固相肽合成 (SPPS)。卡非佐米的合成充分展示了丙二烯酮介导的肽键形成的稳健性,该合成涉及一种罕见的无消旋化/差向异构化的 N 到 C 肽延伸策略。此外,在固体支持物上成功合成模型困难肽 ACP (65-74) 表明该方法与 SPPS 兼容。该方法结合了传统活性酯和偶联剂的优点,同时克服了两种策略的缺点。因此,这种丙二烯酮介导的肽键形成策略代表了肽合成的颠覆性创新。
Straightforward Functionalization of Sulfur-Containing Peptides via 5- and 6-endo-dig Cyclization Reactions
作者:Pavel Arsenyan、Sindija Lapcinska
DOI:10.1055/a-1343-5607
日期:2021.5
peptides containing S–S or S–H bonds by employing N-chlorosuccinimide. The corresponding sulfenyl electrophiles are further utilized in 5- and 6-endo-dig cyclization reactions yielding indolizinium salts, indoles, benzo[b]furans, polyaromatic hydrocarbons (PAHs) and isocoumarins, as well as quinolinones bearing a glutathione moiety. PAH derivatives can be used as selective fluorescent dyes for the
Abstract A new method for the synthesis of 3-thioazaspiro[4,5]trienones was developed using Pd nanoparticle catalysts, which are highly efficient, environmentally friendly and recyclable. Alkynes and thiophene phenols are effectively cyclized by Pd/ZrO2 catalyst under visible light irradiation. The present protocol simply utilizes visible light as the safe and ecofriendly energy source, and the Pd/ZrO2
Visible-light-enabled spirocyclization of alkynes leading to 3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones
作者:Wei Wei、Huanhuan Cui、Daoshan Yang、Huilan Yue、Chenglong He、Yulong Zhang、Hua Wang
DOI:10.1039/c7gc02330h
日期:——
A visible-light-induced strategy has been established for the synthesis of 3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones at room temperature in air.
已在室温下空气中合成3-磺酰基和3-磺基氮杂螺[4,5]三烯酮的可见光诱导策略。
Visible-light-mediated selective thiocyanation/ipso-cyclization/oxidation cascade for the synthesis of thiocyanato-containing azaspirotrienediones
作者:Yuan Chen、Yu-Jue Chen、Zhi Guan、Yan-Hong He
DOI:10.1016/j.tet.2019.130763
日期:2019.12
visible-light-mediated metal-free thiocyanate radicaladdition/ipso-cyclization/oxidation cascade reaction for the synthesis of thiocyanato-containing azaspirotrienediones from N-phenylpropynamides is described. Cheap and readily available ammonium thiocyanate was used as a precursor to the thiocyanate freeradical, which undergoes a radicaladditionreaction with the alkyne, followed by selective ipso-cyclization