Nickel-Catalyzed Reductive 1,3-Diene Formation from the Cross-Coupling of Vinyl Bromides

Author(s):  
Yunfei Sha ◽  
Jiandong Liu ◽  
Liang Wang ◽  
Demin Liang ◽  
Da Wu ◽  
...  

Facile construction of 1,3-dienes building upon cross-electrophile coupling of two open-chain vinyl halides is disclosed in this work, showing moderate chemoselectivities between the terminal bromoalkenes and internal vinyl bromides. The...

Measurement ◽  
2021 ◽  
Vol 174 ◽  
pp. 109083
Author(s):  
Lu Zhang ◽  
Yuntao Qiu ◽  
Xikai Liu ◽  
Liang Chen ◽  
Ning Zhang ◽  
...  

1998 ◽  
Vol 12 (6) ◽  
pp. 835-841
Author(s):  
Cesare Patrone ◽  
Elisabetta Gianazza ◽  
Sabrina Santagati ◽  
Paola Agrati ◽  
Adriana Maggi

Abstract The α-estrogen receptor (ERα) transcriptional activity can be regulated either by binding to the cognate ligand or by intracellular signaling pathways responsive to a variety of factors acting through cell membrane receptors. Studies carried out in HeLa and COS-1 cells demonstrated that the cross-coupling between estrogen and growth factor receptors is mediated by p21ras and requires phosphorylation of a specific serine residue (Ser 118 in the human ERα and Ser 122 in mouse ERα) located in the ERα N-terminal activation function 1 (AF-1). Likewise, in the SK-N-BE neuroblastoma cell line p21ras is involved in the cross-coupling between insulin and ERα receptors. However, in this cell line Ser 122 is not necessary for insulin-dependent activation of unliganded ERα. In addition, after insulin activation, the electrophoretic mobility associated to serine hyperphosphorylation of ERα in SK-N-BE and in COS-1 cells is different. Our study rules out the possibility of tyrosine phosporylation in unliganded ERα activation by means of transactivation studies of ERα tyrosine mutants and analysis of Tyr phosphorylation immunoreactivity. The two cofactors for steroid receptors RIP 140 and SRC-1 do not seem to be specifically involved in the insulin-induced ERα transactivation. The present study demonstrates the possibility of an alternative, cell-specific pathway of cross-coupling between intracellular and membrane receptors, which might be of importance for the understanding of the physiological significance of this mode of activation in the nervous system.


2021 ◽  
Vol 43 (1) ◽  
pp. 95-95
Author(s):  
Rifhat Bibi Rifhat Bibi ◽  
Muhammad Yaseen Muhammad Yaseen ◽  
Haseen Ahmad Haseen Ahmad ◽  
Ismat Ullah Khan Ismat Ullah Khan ◽  
Shaista Parveen Shaista Parveen ◽  
...  

Transition metals mediated cross coupling methodologies provide an extremely powerful versatile pathway in organic syntheses undoubtedly, a facile route for syntheses and derivatization of biologically important heterocycles from easily available precursors. Sonogashira coupling reaction, a leading method to Csp-Csp2 bond formation is one of the most important and rapid pathways to couple aryl/vinyl halides with terminal alkynes. Current research study deals with the synthesis of alkyne substituted quinoxaline derivatives. The quinoxalines class of aromatic heterocycles exhibits a wide variety of important biological potencies. Palladium catalyzed cross coupling process provided an effective synthetic practice for the synthesis of alkyne derivatives of quinoxaline. Vareity of terminal alkynes were coupled with 2-(4-bromophenyl)quinoxaline under optimized conditions for Sonogashira reaction, affording alkyne substituted quinoxaline derivatives in high yields. The optimized reaction conditions for coupling of range of terminal alkyne with quinoxaline basic core render this process significant for designing of medicinally interesting precursors.


2016 ◽  
Vol 81 (8) ◽  
pp. 3329-3334 ◽  
Author(s):  
Meihua Xie ◽  
Shengke Wang ◽  
Jun Wang ◽  
Kuang Fang ◽  
Changqing Liu ◽  
...  

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