scholarly journals Pd-catalyzed intramolecular addition of active methylene compounds to alkynes with subsequent cross-coupling with (hetero)aryl halides

RSC Advances ◽  
2019 ◽  
Vol 9 (68) ◽  
pp. 40152-40167 ◽  
Author(s):  
Aleksandra Błocka ◽  
Paweł Woźnicki ◽  
Marek Stankevič ◽  
Wojciech Chaładaj
Keyword(s):  
Functional Group ◽  
Cross Coupling ◽  
Aryl Halides ◽  
Mechanistic Studies ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Active Methylene Compounds ◽  
Tandem Cyclization ◽  
Rate Limiting ◽  
Active Methylene

A tandem cyclization/coupling of acetylenic active methylene compounds with aryl halides features broad scope and excellent functional group compatibility. Mechanistic studies identified 5-exo-dig cyclization as the rate limiting step.

Triazine-wingtips accelerated NHC-Pd catalysed carbonylative Sonogashira cross-coupling reaction

2021 ◽  
Author(s):  
Kan Zhang ◽  
Yanxiu Yao ◽  
Winjin Sun ◽  
Rui Wen ◽  
Yanyan Wang ◽  
...  
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Heterocyclic Carbenes ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Cross Coupling Reaction ◽  
Efficient Coupling ◽  
Wing Tips ◽  
Rate Limiting ◽  
Ppm Level

The transmetalation as the rate-limiting step was effectively accelerated by newly designed N-heterocyclic carbenes with triazine wing-tips (T-NHC). By using ppm-level precatalyst T-NHC-Pd (8), the highly efficient coupling of aryl...

Thiol−Ene Photopolymerization Mechanism and Rate Limiting Step Changes for Various Vinyl Functional Group Chemistries

2003 ◽  
Vol 36 (21) ◽  
pp. 7964-7969 ◽  
Author(s):  
Neil B. Cramer ◽  
Sirish K. Reddy ◽  
Allison K. O'Brien ◽  
Christopher N. Bowman
Keyword(s):  
Functional Group ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Ornithine Decarboxylase Activity in Cultured Endothelial Cells Stimulated by Serum, Thrombin and Serotonin

1978 ◽  
Vol 39 (02) ◽  
pp. 496-503 ◽  
Author(s):  
P A D’Amore ◽  
H B Hechtman ◽  
D Shepro
Keyword(s):  
Endothelial Cells ◽  
Ornithine Decarboxylase ◽  
Decarboxylase Activity ◽  
Aortic Endothelial Cells ◽  
Ornithine Decarboxylase Activity ◽  
Rate Limiting Step ◽  
Bovine Aortic Endothelial Cells ◽  
Limiting Step ◽  
Rate Limiting ◽  
Serum Serotonin

SummaryOrnithine decarboxylase (ODC) activity, the rate-limiting step in the synthesis of polyamines, can be demonstrated in cultured, bovine, aortic endothelial cells (EC). Serum, serotonin and thrombin produce a rise in ODC activity. The serotonin-induced ODC activity is significantly blocked by imipramine (10-5 M) or Lilly 11 0140 (10-6M). Preincubation of EC with these blockers together almost completely depresses the 5-HT-stimulated ODC activity. These observations suggest a manner by which platelets may maintain EC structural and metabolic soundness.

Dynamics of hepatic and peripheral insulin effects suggest common rate-limiting step in vivo

Diabetes ◽  
1993 ◽  
Vol 42 (2) ◽  
pp. 296-306 ◽  
Author(s):  
D. C. Bradley ◽  
R. A. Poulin ◽  
R. N. Bergman
Keyword(s):  
Rate Limiting Step ◽  
Limiting Step ◽  
Rate Limiting

Kinetics of cyclization of S-ethoxycarbonylmethylisothiouronium chloride to 2-imino-4-thiazolidone

1979 ◽  
Vol 44 (3) ◽  
pp. 912-917 ◽  
Author(s):  
Vladimír Macháček ◽  
Said A. El-bahai ◽  
Vojeslav Štěrba
Keyword(s):  
Hydrochloric Acid ◽  
Dilute Hydrochloric Acid ◽  
Base Catalysis ◽  
General Base ◽  
Rate Limiting Step ◽  
Limiting Step ◽  
Kinetics Of Formation ◽  
Acid Catalyzed ◽  
Rate Limiting ◽  
Kinetics Of

Kinetics of formation of 2-imino-4-thiazolidone from S-ethoxycarbonylmethylisothiouronium chloride has been studied in aqueous buffers and dilute hydrochloric acid. The reaction is subject to general base catalysis, the β value being 0.65. Its rate limiting step consists in acid-catalyzed splitting off of ethoxide ion from dipolar tetrahedral intermediate. At pH < 2 formation of this intermediate becomes rate-limiting; rate constant of its formation is 2 . 104 s-1.

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