Reaction of α-(<i>N</i>-Carbamoyl)alkylcuprates with Propargyl Substrates: Synthetic Route to α-Amino Allenes and Δ<sup>3</sup>-Pyrrolines
作者:R. Karl Dieter、Ningyi Chen、Huayun Yu、Lois E. Nice、Vinayak K. Gore
DOI:10.1021/jo0481405
日期:2005.3.1
Carbamate deprotonation followed by treatment with CuCN·2LiCl affords α-(N-carbamoyl)alkylcuprates which react with propargyl halides, mesylates, tosylates, phosphates, acetates, and epoxides to give α-(N-carbamoyl) allenes via an anti-SN2‘ substitution process. Propargyl halides, sulfonates, and phosphates give good yields of carbamoyl allenes, while the acetates afford low yields. Propargyl substrates
氨基甲酸酯去质子化,然后用CuCN·2LiCl处理,得到α-(N-氨基甲酰基)烷基铜酸酯,它们与炔丙基卤,甲磺酸酯,甲苯磺酸酯,磷酸盐,乙酸酯和环氧化物反应,通过抗S N生成α-(N-氨基甲酰基)丙二烯。2'替代过程。炔丙基卤化物,磺酸盐和磷酸盐给出的氨基甲酰基烯丙基烯的收率高,而乙酸酯的收率低。炔丙基底物在没有严重空间位阻的情况下进行区域特异性S N 2'取代。α-(ñ -氨基甲酰基)丙二烯环化,可以-2-恶唑烷酮或脱保护,得到其可以被环化至Δ游离胺3个-pyrrolines与任一的AgNO 3或Ru3(CO)12。
Structural analogs of tylophora alkaloids may not be functional analogs
Phenanthroindolizidine-based tylophoraalkaloids have been reported to have potential antitumor, anti-immuno and, anti-inflammatory activity. The structure-activity relationships of a series of tylophoraalkaloids were studied to guide future drug design. Our results indicate that although these compounds are structural analogs, their potency of cytotoxicity, selectivity against NF-kappaB signaling
Total Syntheses of the Tylophora Alkaloids Cryptopleurine, (−)-Antofine, (−)-Tylophorine, and (−)-Ficuseptine C
作者:Alois Fürstner、Jason W. J. Kennedy
DOI:10.1002/chem.200600592
日期:2006.9.25
sensitive and multidrug resistant cancer cell lines. The advantages of the chosen route are illustrated by the total syntheses of the phenanthroquinolizidine cryptopleurine (1) and the phenanthroindolizidines (-)-antofine (2), (-)-tylophorine (3), and their only recently isolated congener (-)-ficuseptine C (4). The key steps consist in a Suzuki cross-coupling between a (commercial) boronic acid and a
Regioselective
<i>trans</i>
‐Hydrostannation of Boron‐Capped Alkynes
作者:Romain Melot、Tomas J. Saiegh、Alois Fürstner
DOI:10.1002/chem.202101901
日期:2021.12.6
periphery of the loaded ruthenium catalyst is the likely cause for the excellent regioselectivity observed in the hydrostannation of bench-stable alkynyl-B(aam) derivatives (aam=anthranilamido). The reaction follows a stereochemically unorthodox trans-addition mode and delivers highly versatile gem-dimetalated alkene building blocks for synthesis.