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。
Efficient Synthesis of 3-Chloromethyl-2(5<i>H</i>)-furanones and 3-Chloromethyl- 5,6-dihydropyran-2-ones via the PdCl<sub>2</sub>-Catalyzed Chlorocyclocarbonylation of 2,3- or 3,4-Allenols
作者:Xin Cheng、Xuefeng Jiang、Yihua Yu、Shengming Ma
DOI:10.1021/jo8015677
日期:2008.11.21
was formed between the center carbon atom of the allene moiety and the hydroxyl oxygen, which was established by the X-ray single crystal diffraction study of gamma-lactone 3p. The highly opticallyactive 3-chloromethyl-2(5H)-furanones could be easily prepared from the readily available opticallyactive 2,3-allenols. A mechanism for this reaction was proposed.
γ-lactonization of homopropargyl alcohols via an alkyne deprotonation/boronation/oxidation sequence has been developed. Oxidation of the generated alkynyl boronate affords the corresponding ketene intermediate, which is trapped by the adjacent hydroxy group to furnish the γ-lactone. We have optimized the conditions as well as examined the substrate scope and synthetic applications of this efficient one-pot
Stereoselective Synthesis of Oxacycles via Ruthenium-Catalyzed Atom-Economic Coupling of Propargyl Alcohols and Michael Acceptors
作者:Nabakumar Bera、Shantanu Samanta、Debayan Sarkar
DOI:10.1021/acs.joc.1c01758
日期:2021.12.3
6-endo trig cyclization under acid-catalyzed conditions to deliver the tetrahydro-4H-pyran-4-ones with high diastereoselectivity. An intramolecular aldol condensation under mild basic conditions and palladium-catalyzed oxidative aromatization was developed for the synthesis of hexahydro-6H-isochromen-6-ones and isochromanols, respectively, from highlysubstituted tetrahydro-4H-pyran-4-ones with excellent
Revisiting the Addition of in-situ Nucleophiles to Allenic Ketones: An Entry Towards Synthesis of Benzodioxins
作者:Sushree Ranjan Sahoo、Debayan Sarkar
DOI:10.1002/ejoc.202000076
日期:2020.3.22
A revisit towards regioselective addition of in situ generated negative nucleophiles to allenicketones in the presence of a base. A direct ring annulation towards the benzodioxin skeleton synthesis has been developed. In the process, the obtained E‐vinyl kenones were readily transformed into sulfones and 2,5‐disubstituted oxazole.