Stereoselective Synthesis of Chiral Polycyclic Indolic Architectures through Pd<sup>0</sup>-Catalyzed Tandem Deprotection/Cyclization of Tetrahydro-β-carbolines on Allenes
作者:Valérian Gobé、Xavier Guinchard
DOI:10.1002/chem.201500273
日期:2015.6.1
Enantioenriched N‐allyl tetrahydro‐β‐carbolines were prepared by chiral phosphoric acid‐catalyzed Pictet–Spengler reactions. The compounds undergo Pd0‐catalyzed cyclizationsthrough a tandemdeprotection/cyclization process. The regioselectivity of the attack is controlled by the chain length and by the substitution pattern of the allene function. Products resulting from 5‐exo‐ or 6‐exo‐attack were obtained
通过手性磷酸催化的Pictet-Spengler反应制备了对映体富集的N-烯丙基四氢-β-咔啉。这些化合物通过串联的脱保护/环化过程经历Pd 0催化的环化。攻击的区域选择性由链长和丙二烯官能团的取代模式控制。从5 exo-或6 exo-攻击获得的产物的非对映异构体比例高达95:5。Azepinopyrrido [3,4 b ]吲哚通过7-获得内切-cyclizations。
Domino Formation of Enamines - Intramolecular Cyclizations to 1-Aminotetralins from γ-Arylallene Aldehydes and Amines
1,5-/1,6-Allenals conjugated to an aromatic ring undergo a cyclization, in the presence of an amine, that leads to tricyclic compounds including the 1-aminotetralin scaffold. This domino process combines the in situ formation of the enamine and the cyclization affording the tricyclic 1-aminotetralins in very high diastereoselectivities.
Chemoselective Activities of Fe(III) Catalysts in the Hydrofunctionalization of Allenes
作者:Min Seok Jung、Won Sun Kim、Ye Ho Shin、Ha Jeong Jin、Young Sam Kim、Eun Joo Kang
DOI:10.1021/ol303021d
日期:2012.12.21
A range of tetrahydropyrans and piperidines were produced by Fe(III)-catalyzed intramolecular hydroalkoxylation and hydroamination reactions of allenes. Various Fe catalysts with different counterions were tested. Their activities toward allene and alkene activation depended sensitively on their counterion and reaction conditions. Mechanistic study of the reaction intermediates found a new reaction pattern involving the Fe catalysts and diene substrates.