Domino Formation of Enamines - Intramolecular Cyclizations to 1-Aminotetralins from γ-Arylallene Aldehydes and Amines
摘要:
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.
Reactions Involving Tryptamines and δ-Allenyl Aldehydes: Competition between Pictet-Spengler Reaction and Cyclization to 1-Aminotetralins
作者:Valérian Gobé、Vincent Gandon、Xavier Guinchard
DOI:10.1002/adsc.201701487
日期:2018.3.20
course of Pictet‐Spengler reactionsbetween tryptamines and δ‐allenyl aldehydes. This discovery led to the study of a novel reactivity using aldehydes and secondary amines. DFT calculations show that the cyclization occurs in a stepwise manner that is sufficiently fast to allow high diastereoselectivity. When using allyl‐tryptamines, it is possible to control the reaction, depending on the substituents
Nickel-catalyzed couplings and cyclizations involving allenes, aldehydes, and organozincs
作者:Minsoo Song、John Montgomery
DOI:10.1016/j.tet.2005.08.066
日期:2005.11
Cyclizations of allenyl aldehydes and intermolecular couplings of allenes and aldehydes provide a direct procedure for the preparation of homoallylic alcohols. The couplings and cyclizations involve the use of diorganozine reagents as reducing agents and Ni(COD)(2) as the catalyst. (c) 2005 Elsevier Ltd. All rights reserved.
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.