scholarly journals Synthesis of 1-Hydroxyyohimbine and Its Novel Skeletal Rearrangement Reaction into Oxindole Derivatives

Heterocycles ◽  
2001 ◽  
Vol 55 (7) ◽  
pp. 1237 ◽  
Author(s):  
Masanori Somei ◽  
Koichi Noguchi ◽  
Fumio Yamada
Keyword(s):  
Skeletal Rearrangement ◽  
Rearrangement Reaction

scholarly journals Gold-Catalyzed Cyclization/Intermolecular Methylene Transfer ­Sequence of O-Propargylic Oximes Derived from Glyoxylates

Synlett ◽  
2018 ◽  
Vol 30 (04) ◽  
pp. 393-396 ◽  
Author(s):  
Shinya Gima ◽  
Keigo Shiga ◽  
Masahiro Terada ◽  
Itaru Nakamura
Keyword(s):  
Bond Cleavage ◽  
Ester Group ◽  
Mechanistic Studies ◽  
Skeletal Rearrangement ◽  
Reaction Proceeds ◽  
Rearrangement Reaction ◽  
High Yields

We successfully extended our gold-catalyzed skeletal rearrangement reaction of O-propargylic oximes through C=N bond cleavage to include substrates having an ester group on the oxime moiety, affording the corresponding 2-isoxazolines having an alkoxycarbonylmethylene group at the 4-position in good to high yields. Our mechanistic studies indicated that the transfer of the alkoxycarbonylmethylene group proceeded in an intermolecular manner, confirming that the reaction proceeds through cyclization followed by intermolecular transfer of the alkoxycarbonylmethylene group.

scholarly journals Au-catalyzed skeletal rearrangement of O-propargylic oximes via N–O bond cleavage with the aid of a Brønsted base cocatalyst

2019 ◽  
Vol 10 (20) ◽  
pp. 5283-5289 ◽  
Author(s):  
Keigo Shiga ◽  
Ilya D. Gridnev ◽  
Masahiro Terada ◽  
Itaru Nakamura
Keyword(s):  
Bond Cleavage ◽  
Skeletal Rearrangement ◽  
Rearrangement Reaction ◽  
Brønsted Base

Au-catalyzed skeletal rearrangement reaction of O-propargylic oxime proceeded via N–O bond cleavage with the aid of a Brønsted base cocatalyst.

Novel skeletal rearrangement reaction of tetrasilanes with aryl isocyanides

1989 ◽  
pp. 1494 ◽  
Author(s):  
Yoshihiko Ito ◽  
Michinori Suginome ◽  
Masahiro Murakami ◽  
Motoo Shiro
Keyword(s):  
Skeletal Rearrangement ◽  
Rearrangement Reaction

ChemInform Abstract: Novel Skeletal Rearrangement Reaction of Tetrasilanes with Aryl Isocyanides.

ChemInform ◽  
1990 ◽  
Vol 21 (14) ◽  
Author(s):  
Y. ITO ◽  
M. SUGINOME ◽  
M. MURAKAMI ◽  
M. SHIRO
Keyword(s):  
Skeletal Rearrangement ◽  
Rearrangement Reaction

Synthesis, Structure and Reactivities of Pentacoordinated Phosphorus–Boron Bonded Compounds

2020 ◽  
Author(s):  
Nathan O'Brien ◽  
Naokazu Kano ◽  
Nizam Havare ◽  
Ryohei Uematsu ◽  
Romain Ramozzi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Ring Expansion ◽  
Bicyclic Compound ◽  
Compound A ◽  
Ligand System ◽  
Large Bulk ◽  
Rearrangement Reaction ◽  
Hydride Abstraction ◽  
Pentacoordinated Phosphorus ◽  
Acids And Bases

<div>The isolation and reactivities of two pentacoordinated phosphorus–tetracoordinated boron bonded compounds were</div><div>explored. A strong Lewis acidic boron reagent and electron-withdrawing ligand system were required to form the</div><div>pentacoordinated phosphorus state of the P–B bond. The first compound, a phosphoranyl-trihydroborate, gave a THF</div><div>stabilised phosphoranyl-borane intermediate upon a single hydride abstraction in THF. This compound could undergo a</div><div>unique rearrangement reaction, that involved a two-fold ring expansion, to give an unusual fused bicyclic compound or it</div><div>could act as a mono-hydroboration reagent. The hydroboration reactivity of the intermediate was found to be more reactive</div><div>towards alkynes over alkenes with good to moderate regioselectivity towards the terminal carbon. The second compound,</div><div>a phosphoranyl-triarylborate, was found to have a vastly different reactivity to the trihydroborate as it was highly stable</div><div>towards acids and bases. This is thought to be due to the large bulk around the P–B bond as shown in the crystal structure</div>

scholarly journals Oxidative cyclo-rearrangement of helicenes into chiral nanographenes

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chengshuo Shen ◽  
Guoli Zhang ◽  
Yongle Ding ◽  
Na Yang ◽  
Fuwei Gan ◽  
...  
Keyword(s):  
Functional Materials ◽  
Optical Devices ◽  
Oxidative Cyclization ◽  
Synthetic Chemistry ◽  
Aromatic Rings ◽  
Cyclization Reactions ◽  
Rearrangement Reaction ◽  
Skeletal Reconstruction ◽  
Gradual Release

AbstractNanographenes are emerging as a distinctive class of functional materials for electronic and optical devices. It is of remarkable significance to enrich the precise synthetic chemistry for these molecules. Herein, we develop a facile strategy to recompose helicenes into chiral nanographenes through a unique oxidative cyclo-rearrangement reaction. Helicenes with 7~9 ortho-fused aromatic rings are firstly oxidized and cyclized, and subsequently rearranged into nanographenes with an unsymmetrical helicoid shape through sequential 1,2-migrations. Such skeletal reconstruction is virtually driven by the gradual release of the strain of the highly distorted helicene skeleton. Importantly, the chirality of the helicene precursor can be integrally inherited by the resulting nanographene. Thus, a series of chiral nanographenes are prepared from a variety of carbohelicenes and heterohelicenes. Moreover, such cyclo-rearrangement reaction can be sequentially or simultaneously associated with conventional oxidative cyclization reactions to ulteriorly enrich the geometry diversity of nanographenes, aiming at innovative properties.

Ruthenium-Catalyzed Cycloisomerization of o-(Ethynyl)phenylalkenes to Diene Derivatives via Skeletal Rearrangement.

ChemInform ◽  
2005 ◽  
Vol 36 (15) ◽  
Author(s):  
Reniguntala J. Madhushaw ◽  
Ching-Yu Lo ◽  
Chun-Wei Hwang ◽  
Ming-Der Su ◽  
Hung-Chin Shen ◽  
...  
Keyword(s):  
Skeletal Rearrangement

Catalyst-Free [2,3]-Sigmatropic Rearrangement Reactions of Photochemically Generated Ammonium Ylides

Synthesis ◽  
2019 ◽  
Vol 51 (23) ◽  
pp. 4348-4358 ◽  
Author(s):  
Fang Li ◽  
Feifei He ◽  
Rene M. Koenigs
Keyword(s):  
Visible Light ◽  
Sigmatropic Rearrangement ◽  
Tertiary Amines ◽  
Amino Esters ◽  
Catalyst Free ◽  
Rearrangement Reaction ◽  
Rearrangement Reactions ◽  
Free Ammonium

The rearrangement reaction of ammonium ylides furnishes valuable α,α-disubstituted amino esters. In this work, we describe the visible-light photolysis reaction of aryldiazoacetates in the presence of tertiary amines that react via a free ammonium ylide in a sigmatropic rearrangement reaction to provide amino esters in moderate to very good yields (33 examples, up to 97% yield).

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