Unified Synthesis of Polycyclic Alkaloids by Complementary Carbonyl Activation**
作者:Guoli He、Benjamin List、Mathias Christmann
DOI:10.1002/anie.202102518
日期:2021.6.7
A complementary dual carbonyl activation strategy for the synthesis of polycyclic alkaloids has been developed. Successful applications include the synthesis of tetracyclic alkaloids harmalanine and harmalacinine, pentacyclic indoloquinolizidine alkaloid nortetoyobyrine, and octacyclic β-carboline alkaloid peganumine A. The latter synthesis features a protecting-group-free assembly and an asymmetric
已经开发出用于合成多环生物碱的互补双羰基活化策略。成功的应用包括四环生物碱骆驼蓬菌素和骆驼蓬菌素、五环吲哚喹啉西啶生物碱去甲代拜林和八环β-咔啉生物碱peganumine A的合成。后者的合成具有无保护基组装和不对称二磺酰亚胺催化环化的特点。此外,还实现了 hirsutine、deplancheine、10-desbromoarborescidine A 和 oxindole 生物碱钩藤碱和异钩藤碱的正式合成。最终完成了小檗碱生物碱ilicifoline B的简捷合成。
Studies Dealing with Thionium Ion Promoted Mannich Cyclization Reactions
作者:Albert Padwa、Alex G. Waterson
DOI:10.1021/jo991414h
日期:2000.1.1
six-membered alkylthio-substituted lactams as transient intermediates. Further reaction of the alkylthio-substituted lactam with DMTSF generates an N-acyliminium ion, which undergoes cyclization with the tethered aromatic ring to produce an azapolycyclic ring system. Related cyclization sequences occur when amido thioacetals possessing simple olefinic tethers were used. The overall procedure represents an efficient
Parham-type cyclization and nucleophilic addition - N-acyliminium ion cyclization sequences for the construction of the isoquinoline nucleus
作者:M.Isabel Collado、Nuria Sotomayor、María-Jesús Villa、Esther Lete
DOI:10.1016/0040-4039(96)01321-4
日期:1996.8
Efficient methodologies based on the nucleophilic addition-N-acyliminium ioncyclization and the Parham-typecyclizationsequences of N-phenethylimides 1 and 2 are reported for the synthesis of a variety of heterocyclic systems: benzo[a]quinolizidones and their 2-oxa analogs, isoindoloisoquinolones, dibenzo[a,h]quinolizidones, thiazolo-, oxazolo-, and imidazolo [4,3-a]isoquinolones.
Synthesis and stereochemical study of cis- and trans-1-(3′-substituted-propyl)benzo[a]quinolizidine
作者:Jenõ Kóbor、Pál Sohár、Ferenc Fülöp
DOI:10.1016/s0040-4020(01)85022-5
日期:1994.4
From 1-methyl-6,7-dimethoxy-3,4-dihydroisoquinoline with methyl or ethyl acrylate or with acrylonitrile, via Michael addition products, cis- and trans-1-(3′-substituted-propyl)benzo[a]quinolizidinones and quinolizidines were prepared. The relative configurations and the predominant conformations were determined by means of 1H and 13C NMR spectroscopy, with the application of DR, DNOE and 2D HSC measurements
由1-甲基-6,7-二甲氧基-3,4-二氢异喹啉与丙烯酸甲酯或丙烯酸乙酯或与丙烯腈经迈克尔加成产物,形成顺式和反式-1-(3'-取代-丙基)苯并[a]喹喔啉酮制备了喹喔啉类药物。借助DR,DNOE和2D HSC测量,通过1 H和13 C NMR光谱测定相对构型和主要构象。
Metalation <i>vs </i>Nucleophilic Addition in the Reactions of <i>N</i>-Phenethylimides with Organolithium Reagents. Ready Access to Isoquinoline Derivatives <i>via</i> <i>N</i>-Acyliminium Ions and Parham-Type Cyclizations
作者:M. Isabel Collado、Izaskun Manteca、Nuria Sotomayor、María-Jesús Villa、Esther Lete
DOI:10.1021/jo962155o
日期:1997.4.1
Sequential carbophilic addition of organolithium reagents and N-acyliminiumioncyclization of N-phenethylimides 1 affords the substituted isoquinolones 3 in high yields, with the possibility of varying the substituent at the C-1 position of the isoquinoline ring by changing the organolithium reagent. Ready access to the isoquinolinenucleus via Parham-typecyclization of imides 2 is also described