Highly Diastereo-, α-Regioselective Catalyst-Free Construction of Adjacent Dispirobisoxindoles with Three Contiguous Quaternary Carbon Centers

Synthesis ◽  
2018 ◽  
Vol 51 (03) ◽  
pp. 683-692 ◽  
Author(s):  
Yan Jiang ◽  
Min-Yi Tian ◽  
Xiong-Li Liu ◽  
Shun-Qin Chang ◽  
Sheng-Wen Xu ◽  
...  
Keyword(s):  
Small Molecules ◽  
Cyclization Reaction ◽  
Bioactive Molecules ◽  
Quaternary Carbon ◽  
Reaction Sequence ◽  
Carbon Centers ◽  
Catalyst Free ◽  
Free Construction

A new methodology was developed for the highly diastereoselective construction of dispirobisoxindole scaffolds via a domino α-regioselective Michael/cyclization reaction sequence of 3-isothiocyanato oxindoles and isatylidene malononitriles under catalyst-free conditions. Complex polycyclic oxindoles featuring two side-by-side oxindole skeletons and three contiguous quaternary carbon centers were synthesized in up to 95% yield and >20:1 dr. This protocol could provide libraries of stereochemically rich small molecules that will help in the search for new bioactive molecules.

scholarly journals Catalyst-free carbosilylation of alkenes using silyl boronates and organic fluorides via selective C-F bond activation

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jun Zhou ◽  
Bingyao Jiang ◽  
Yamato Fujihira ◽  
Zhengyu Zhao ◽  
Takanori Imai ◽  
...  
Keyword(s):  
Double Bond ◽  
Bond Activation ◽  
Single Step ◽  
Side Chain ◽  
Side Reactions ◽  
Quaternary Carbon ◽  
Selective Activation ◽  
Carbon Centers ◽  
Catalyst Free ◽  
Powerful Strategy

AbstractA regioselective carbosilylation of alkenes has emerged as a powerful strategy to access molecules with functionalized silylated alkanes, by incorporating silyl and carbon groups across an alkene double bond. However, to the best of our knowledge, organic fluorides have never been used in this protocol. Here we disclose the catalyst-free carbosilylation of alkenes using silyl boronates and organic fluorides mediated by tBuOK. The main feature of this transformation is the selective activation of the C-F bond of an organic fluoride by the silyl boronate without undergoing potential side-reactions involving C-O, C-Cl, heteroaryl-CH, and even CF3 groups. Various silylated alkanes with tertiary or quaternary carbon centers that have aromatic, hetero-aromatic, and/or aliphatic groups at the β-position are synthesized in a single step from substituted or non-substituted aryl alkenes. An intramolecular variant of this carbosilylation is also achieved via the reaction of a fluoroarene with a ω-alkenyl side chain and a silyl boronate.

Quaternary Carbon Center Forming [3 + 2] Cyclization Reaction by Adjusting the Substituents of Substrates

2019 ◽  
Vol 84 (21) ◽  
pp. 13871-13880 ◽  
Author(s):  
Xie-Chao Yang ◽  
Jin-Yu Liu ◽  
Zhen Liu ◽  
Xiu-Qin Hu ◽  
Peng-Fei Xu
Keyword(s):  
Cyclization Reaction ◽  
Quaternary Carbon

Stereocontrolled Synthesis of Highly Functionalized Quaternary Carbon Centers: A Route to α-Substituted Serines

2009 ◽  
Vol 121 (23) ◽  
pp. 4266-4269 ◽  
Author(s):  
Xavier Ariza ◽  
Josep Cornellà ◽  
Mercè Font-Bardia ◽  
Jordi Garcia ◽  
Jordi Ortiz ◽  
...  
Keyword(s):  
Quaternary Carbon ◽  
Carbon Centers ◽  
Stereocontrolled Synthesis

Alkylation of (η6-arene) - Ru(II) complexes: Construction of benzylic quaternary carbon centers

1999 ◽  
Vol 40 (12) ◽  
pp. 2251-2254 ◽  
Author(s):  
F.Christopher Pigge ◽  
Shiyue Fang ◽  
Nigam P Rath
Keyword(s):  
Quaternary Carbon ◽  
Carbon Centers

scholarly journals Synthesis of Quaternary Carbon Centers via Hydroformylation

2010 ◽  
Vol 132 (34) ◽  
pp. 11841-11843 ◽  
Author(s):  
X. Sun ◽  
K. Frimpong ◽  
K. L. Tan
Keyword(s):  
Quaternary Carbon ◽  
Carbon Centers
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