A Pd-catalyzed reaction of vinyl iodides and N-tosylhydrazones that assembles eta(3)-allyl ligands through carbene insertion is demonstrated. Intramolecular trapping with nitrogen nucleophiles generates good yields of cinnamyl and pentadienyl amines like those found in alkaloid natural products. Carbenylative amination was the key reaction to complete the synthesis of the alkaloid caulophyllumine B. Migratory insertion was biased to provide allylamines with optical purity up to 64% ee, but in a lower yield.
Palladium‐Catalysed Cyclisation of
<i>N</i>
‐Alkynyl Aminomalonates
作者:Wilfried Hess、Jonathan W. Burton
DOI:10.1002/chem.201001951
日期:2010.11.2
Go around in (hetero)cycles! The palladium‐catalysed tandem cyclisation/coupling reaction of alkynyl‐ and alkenyl‐substituted aminomalonates leads to highly functionalised pyrrolidines and piperidines in good yield (see scheme). The reaction allows efficient access to a broad range of synthetically valuable building blocks.
Mild generation of vinylidene carbene from α-amino nitrile is the basis of a new synthesis of homopropargylamines.
从α-氨基腈中产生乙烯基碳烯是合成同异丙炔胺的新方法的基础。
Mild Metal-Free Hydrosilylation of Secondary Amides to Amines
作者:Pei-Qiang Huang、Qi-Wei Lang、Yan-Rong Wang
DOI:10.1021/acs.joc.6b00572
日期:2016.5.20
tetrahydro-5-oxo-2-furaneamides yielded 5-(aminomethyl)dihydrofuran-2(3H)-ones in a racemization-free manner. The latter were converted in one pot to N-protected 5-hydroxypiperidin-2-ones, which are building blocks for the synthesis of many natural products. Further elaboration of an intermediate led to a concise four-step synthesis of (−)-epi-pseudoconhydrine.
Tf 2 O的酰胺活化与B(C 6 F 5)3催化的氢硅烷基化与TMDS的结合构成了一种在温和条件下将一阶仲酰胺还原为胺的方法。该方法对减少多种类型的底物显示出广泛的适用性,并且对于许多敏感的官能团显示出良好的相容性和优异的化学选择性。从另一种合成方法获得的多官能化的α,β-不饱和酰胺的还原以及C–H官能化的产物可产生相应的胺,收率好至极好。化学选择性还原对映体纯的(ee> 99%)四氢-5-氧代-2-呋喃酰胺,生成5-(氨基甲基)二氢呋喃-2(3 H)-以无消旋的方式进行。将后者在一个罐中转化为N保护的5-羟基哌啶-2-酮,这是合成许多天然产物的基础。进一步精制中间体导致(-)- Epi- pseudoconhydrine的简洁的四步合成。
Catalytic One-Pot Synthesis of Cyclic Amidines by Virtue of Tandem Reactions Involving Intramolecular Hydroamination under Mild Conditions
作者:Sukbok Chang、Minjae Lee、Doo Young Jung、Eun Jeong Yoo、Seung Hwan Cho、Sun Kyu Han
DOI:10.1021/ja064788i
日期:2006.9.1
A newsynthetic methodology for the generation of cyclic amidines has been developed by the reaction of 1,n-aminoalkynes with electron-deficient azides using a ruthenium catalyst at ambient temperature. The reaction proceeds most likely via a tandem sequence of intramolecular hydroamination of aminoalkynes, cycloaddition of azides with the resulting enamines, and rearrangement of triazoline intermediates
Synthetic evolutions in the nucleophilic addition to alkynes
作者:Bo Xu、Weibo Wang、Le-Ping Liu、Junbin Han、Zhuang Jin、Gerald B. Hammond
DOI:10.1016/j.jorganchem.2010.09.025
日期:2011.1
fluorine-engendered cationic gold catalysis. In addition, we have conducted the synthesis of O-heterocycles through a gold-catalyzed tandem addition/cycloisomerization sequence, the synthesis of N-heterocycles through a copper-catalyzed cyclization-triggered addition of alkynes, and a green synthesis of thioethers ‘on water’ without catalyst or initiator. These nucleophilic synthetic evolutions, catapulted by a simple