Stereoselective synthesis of highly congested tetralin-fused spirooxindoles with hydroxy group: Pseudo oxygen atom induced hydride shift/cyclization process

2021 ◽  
pp. 153408
Author(s):  
Dan Sakai ◽  
Mizuki Machida ◽  
Keiji Mori
Keyword(s):  
Oxygen Atom ◽  
Hydroxy Group ◽  
Stereoselective Synthesis ◽  
Hydride Shift ◽  
Cyclization Process

scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

scholarly journals Stereoselective Synthesis of Highly-Congested Tetralin-Fused Spirooxindoles with Hydroxyl Group: Net Oxygen Atom Induced Hydride Shift/cyclization Process.

2021 ◽  
Author(s):  
Dan Sakai ◽  
mizuki machida ◽  
Keiji Mori
Keyword(s):  
Reaction Mechanism ◽  
Nitrogen Atom ◽  
Oxygen Atom ◽  
Stereoselective Synthesis ◽  
Hydroxyl Group ◽  
Target Structure ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Stereogenic Centers

Highly stereoselective synthesis of tetralin-fused spirooxindoles with two contiguous stereogenic centers. In the present reaction, not only [1,5]-hydride shift/cyclization process, but also replacemnt of nitrogen atom to oxygen atom ocurred smoothly to give target structure with hydroxy grop in good chemical yields with good to excellent diastereoselectivities (up to d.r. = >20:1). Investigation of the reaction mechanism suggested that this “atom-replacement” event ocurred via the iminium cation intermediates.

scholarly journals Stereoselective synthesis of tricyclic compounds by intramolecular palladium-catalyzed addition of aryl iodides to carbonyl groups

2016 ◽  
Vol 12 ◽  
pp. 1236-1242 ◽  
Author(s):  
Jakub Saadi ◽  
Christoph Bentz ◽  
Kai Redies ◽  
Dieter Lentz ◽  
Reinhold Zimmer ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Stereoselective Synthesis ◽  
Carbonyl Groups ◽  
Relative Configuration ◽  
X Ray ◽  
Cyclization Process ◽  
Tricyclic Compounds ◽  
Methoxycarbonyl Group ◽  
Palladium Catalyzed ◽  
Group A

Starting from γ-ketoesters with an o-iodobenzyl group we studied a palladium-catalyzed cyclization process that stereoselectively led to bi- and tricyclic compounds in moderate to excellent yields. Four X-ray crystal structure analyses unequivocally defined the structure of crucial cyclization products. The relative configuration of the precursor compounds is essentially transferred to that of the products and the formed hydroxy group in the newly generated cyclohexane ring is consistently in trans-arrangement with respect to the methoxycarbonyl group. A transition-state model is proposed to explain the observed stereochemical outcome. This palladium-catalyzed Barbier-type reaction requires a reduction of palladium(II) back to palladium(0) which is apparently achieved by the present triethylamine.

Catalyst-free construction of spiro [benzoquinolizidine-chromanones] via a tandem condensation/1,5-hydride transfer/cyclization process

2020 ◽  
Vol 18 (43) ◽  
pp. 8839-8843
Author(s):  
Siyuan Liu ◽  
Hang Wang ◽  
Baomin Wang
Keyword(s):  
Hydride Transfer ◽  
Catalyst Free ◽  
Highly Efficient ◽  
Hydride Shift ◽  
Cyclization Process ◽  
Free Construction

A highly efficient and quite mild protocol to achieve spiro [benzoquinoline-chromanones] through a catalyst-free condensation/[1,5]-hydride shift/6-endo cyclization sequence was developed.

Stereoselective synthesis of 2,3-disubstituted indoline, pyrrolidine and cyclic ether-fused 1,2-dihydroquinoline derivatives using alkyne iminium ion cyclization of vinylogous carbamates: switch of regioselectivity using an internal hydroxy group as a nucleophile

2015 ◽  
Vol 51 (71) ◽  
pp. 13623-13626 ◽  
Author(s):  
Santosh J. Gharpure ◽  
V. Prasath ◽  
Vinod Kumar
Keyword(s):  
Hydroxy Group ◽  
Stereoselective Synthesis ◽  
Cyclic Ether ◽  
Iminium Ion

TMSOTf promoted alkyne iminium ion cyclization of vinylogous carbamates gives stereoselective access to indolines, pyrrolidines and dihydroquinolines.

Stereoselective synthesis of novel antiproliferative steroidal (E, E) dienamides through a cascade aldol/cyclization process

Steroids ◽  
2013 ◽  
Vol 78 (11) ◽  
pp. 1134-1140 ◽  
Author(s):  
Bin Yu ◽  
Xiao-Nan Sun ◽  
Xiao-Jing Shi ◽  
Ping-Ping Qi ◽  
Yuan Fang ◽  
...  
Keyword(s):  
Stereoselective Synthesis ◽  
Cyclization Process ◽  
Aldol Cyclization
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