scholarly journals BAKERS YEAST CATALYZED AND ULTRASOUND ACCELERATED SYNTHESIS OF 2-AMINO-2-CHROMENES

2021 ◽  
Vol 9 (01) ◽  
pp. 189-195
Author(s):  
Balaji S. Londhe ◽  
◽  
Santosh L. Khillare ◽  
Avinash M. Nalawade ◽  
Ramrao A. Mane ◽  
...  
Keyword(s):  
Dual Role ◽  
Yeast Cells ◽  
Side Reactions ◽  
Efficient Synthesis ◽  
Neutral Conditions

In the present work, bakers yeast catalyzed efficient synthesis of 2-amino-2-chromenes in methanol is presented. Here the ultrasonication has dual role i.e. as a source of energy for the reaction and tool for the disruption of the yeast cells. The cyclocondensation has been essentially carried under neutral conditions, thus reducing the possibility of unwanted side reactions.

Ni(0)-Catalyzed α-Allylic Alkylation of Regular Ketones with 1,3-Dienes under pH and Redox-neutral Conditions

2019 ◽  
Author(s):  
Tiantian Chen ◽  
Yang Yang ◽  
Liyu Xie ◽  
Haijian Yang ◽  
Guangbin Dong ◽  
...  
Keyword(s):  
Oxidative Addition ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Dual Role ◽  
Allylic Alkylation ◽  
Cross Coupling Reaction ◽  
Neutral Conditions

<p>We report a Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A variety of a-allylic alkylation products were formed in an 1,2-addition manner with excellent regioselectivity. Water was found to significantly accelerate this transformation. A HO-Ni-H species generated from oxidative addition of Ni(0) to H<sub>2</sub>O is proposed to play a “dual role” in activating both the ketone and the diene substrate.</p>

scholarly journals Dual role of polyphosphoric acid-activated nitroalkanes in oxidative peri-annulations: efficient synthesis of 1,3,6,8-tetraazapyrenes

RSC Advances ◽  
2017 ◽  
Vol 7 (48) ◽  
pp. 29927-29932 ◽  
Author(s):  
Alexander V. Aksenov ◽  
Dmitrii S. Ovcharov ◽  
Nicolai A. Aksenov ◽  
Dmitrii A. Aksenov ◽  
Oleg N. Nadein ◽  
...  
Keyword(s):  
Polyphosphoric Acid ◽  
Dual Role ◽  
The Novel ◽  
Efficient Synthesis

Electrophilically activated nitroalkanes play a dual role in the novel reaction with diaminoperimidines, promoting their oxidative peri-annulation to access tetraazapyrenes.

Ni(0)-Catalyzed α-Allylic Alkylation of Regular Ketones with 1,3-Dienes under pH and Redox-neutral Conditions

2019 ◽  
Author(s):  
Tiantian Chen ◽  
Yang Yang ◽  
Liyu Xie ◽  
Haijian Yang ◽  
Guangbin Dong ◽  
...  
Keyword(s):  
Oxidative Addition ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Dual Role ◽  
Allylic Alkylation ◽  
Cross Coupling Reaction ◽  
Neutral Conditions

<p>We report a Ni(0)-catalyzed cross coupling reaction between simple ketones and 1,3-dienes. A variety of a-allylic alkylation products were formed in an 1,2-addition manner with excellent regioselectivity. Water was found to significantly accelerate this transformation. A HO-Ni-H species generated from oxidative addition of Ni(0) to H<sub>2</sub>O is proposed to play a “dual role” in activating both the ketone and the diene substrate.</p>

scholarly journals A dual role for K63-linked ubiquitin chains in multivesicular body biogenesis and cargo sorting

2012 ◽  
Vol 23 (11) ◽  
pp. 2170-2183 ◽  
Author(s):  
Zoi Erpapazoglou ◽  
Manel Dhaoui ◽  
Marina Pantazopoulou ◽  
Francesca Giordano ◽  
Muriel Mari ◽  
...  
Keyword(s):  
Ubiquitin Ligase ◽  
Transmembrane Proteins ◽  
Multivesicular Body ◽  
Dual Role ◽  
Yeast Cells ◽  
Endosomal Sorting ◽  
Binding Domains ◽  
Double Function ◽  
Ubiquitin Binding ◽  
Cargo Sorting

In yeast, the sorting of transmembrane proteins into the multivesicular body (MVB) internal vesicles requires their ubiquitylation by the ubiquitin ligase Rsp5. This allows their recognition by the ubiquitin-binding domains (UBDs) of several endosomal sorting complex required for transport (ESCRT) subunits. K63-linked ubiquitin (K63Ub) chains decorate several MVB cargoes, and accordingly we show that they localize prominently to the class E compartment, which accumulates ubiquitylated cargoes in cells lacking ESCRT components. Conversely, yeast cells unable to generate K63Ub chains displayed MVB sorting defects. These properties are conserved among eukaryotes, as the mammalian melanosomal MVB cargo MART-1 is modified by K63Ub chains and partly missorted when the genesis of these chains is inhibited. We show that all yeast UBD-containing ESCRT proteins undergo ubiquitylation and deubiquitylation, some being modified through the opposing activities of Rsp5 and the ubiquitin isopeptidase Ubp2, which are known to assemble and disassemble preferentially K63Ub chains, respectively. A failure to generate K63Ub chains in yeast leads to an MVB ultrastructure alteration. Our work thus unravels a double function of K63Ub chains in cargo sorting and MVB biogenesis.

A Dual Role for Intracellular Trehalose in the Resistance of Yeast Cells to Water Stress

Cryobiology ◽  
1999 ◽  
Vol 39 (1) ◽  
pp. 80-87 ◽  
Author(s):  
Fumihiko Sano ◽  
Naoki Asakawa ◽  
Yoshio Inoue ◽  
Minoru Sakurai
Keyword(s):  
Water Stress ◽  
Dual Role ◽  
Yeast Cells
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