Formation of an Unusual Bis(diguanidinate) Ligand via Nucleophilic Attack of a Guanidinate onto a Carbodiimide

2014 ◽  
Vol 67 (7) ◽  
pp. 1030 ◽  
Author(s):  
Rebecca L. Melen ◽  
Hayley R. Simmonds ◽  
Hubert Wadepohl ◽  
Paul T. Wood ◽  
Lutz H. Gade ◽  
...  

During an investigation of the synthesis of the new mono- and bis(guanidinate) complexes [{iPr2NC(···NiPr)2}GaCl2] (2) and [{iPr2NC(···NiPr)2}2GaCl] (3) from the in situ reactions of the lithium guanidinate [{iPr2NC(···NiPr)2}Li]n (1) with GaCl3, an unexpected new guanidinate expansion reaction was uncovered in which it is found that the nucleophilic addition of 2 to the carbodiimide, iPrN=C=NiPr, gives [iPrN{C(NiPr)=NiPr}{C(=NiPr)NiPr2}GaCl2] (4), containing an unusual bis(diguanidinate) ligand.

2020 ◽  
Vol 18 (46) ◽  
pp. 9526-9537
Author(s):  
Yun Luo ◽  
Zhicheng Fu ◽  
Xingyang Fu ◽  
Changle Du ◽  
Jiaxi Xu

Microwave-assisted and improved periselective synthesis of benzo-δ-phosphinolactones through the nucleophilic attack of in situ generated triarylphosphenes with aldehydes and ketones followed by intramolecular nucleophilic addition.


Synthesis ◽  
2020 ◽  
Author(s):  
Ikyon Kim ◽  
Sung June Kim ◽  
Sunhee Lee

AbstractBroadening of nitrogen-fused heteroaromatic chemical space such as indolizine and pyrrolo[1,2-a]pyrazine was achieved via FeCl­3-catalyzed nucleophilic addition of these N-fused aromatic compounds to a wide range of azolinium systems generated in situ, leading to novel N-fused heteroaromatic scaffolds with dearomatized N-heterocyclic substituents regioselectively. Nucleophilic addition of indolizines and pyrrolo[1,2-a]pyrazines mainly occurred at the C1 position of the isoquinoliniums and at the C4 site of the quinoliniums.


2021 ◽  
Vol 203 ◽  
pp. 109538
Author(s):  
Boan Xu ◽  
Ping Jiang ◽  
Shaoning Geng ◽  
Yilin Wang ◽  
Jintian Zhao ◽  
...  

2016 ◽  
Vol 113 (28) ◽  
pp. 7722-7726 ◽  
Author(s):  
Gavin O. Jones ◽  
Alexander Yuen ◽  
Rudy J. Wojtecki ◽  
James L. Hedrick ◽  
Jeannette M. García

It is estimated that ∼2.7 million tons poly(carbonate)s (PCs) are produced annually worldwide. In 2008, retailers pulled products from store shelves after reports of bisphenol A (BPA) leaching from baby bottles, reusable drink bottles, and other retail products. Since PCs are not typically recycled, a need for the repurposing of the PC waste has arisen. We report the one-step synthesis of poly(aryl ether sulfone)s (PSUs) from the depolymerization of PCs and in situ polycondensation with bis(aryl fluorides) in the presence of carbonate salts. PSUs are high-performance engineering thermoplastics that are commonly used for reverse osmosis and water purification membranes, medical equipment, as well as high temperature applications. PSUs generated through this cascade approach were isolated in high purity and yield with the expected thermal properties and represent a procedure for direct conversion of one class of polymer to another in a single step. Computational investigations performed with density functional theory predict that the carbonate salt plays two important catalytic roles in this reaction: it decomposes the PCs by nucleophilic attack, and in the subsequent polyether formation process, it promotes the reaction of phenolate dimers formed in situ with the aryl fluorides present. We envision repurposing poly(BPA carbonate) for the production of value-added polymers.


Author(s):  
Monisha Singha ◽  
Prabuddha Bhattacharya ◽  
Debashis Ray ◽  
Amit Basak

Nucleophilic addition to p-benzynes, derived via Bergman Cyclization has become a topic of keen interest. Studying the regioselectivity in such addition can reveal important information regarding the parameters controlling such...


Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 554
Author(s):  
Fehmi Nair ◽  
Mustafa Hamamcı

The objective of this study is to investigate the impact behavior of iron-based composites reinforced with boron carbide (B4C) particles and in-situ synthesized iron borides (Fe2B/FeB). The composite specimens (Fe/B4C) were fabricated by hot-pressing under a pressure of 250 MPa at 500 °C, and sintered at a temperature of 1000 °C. The effects of the reinforcement ratio on the formation of in-situ borides and impact behavior were investigated by means of different volume fractions of B4C inside the iron matrix: 0% (un-reinforced), 5%, 10%, 20%, and 30%. Drop-weight impact tests were performed by an instrumented Charpy impactor on reinforced and un-reinforced test specimens. The results of the impact tests were supported with microstructural and fractographical analysis. As a result of in-situ reactions between the Fe matrix and B4C particles, Fe2B phases were formed in the iron matrix. The iron borides, formed in the iron matrix during sintering, heavily affected the hardness and the morphology of the fractured surface. Due to the high amount of B4C (over 10%), porosity played a major role in decreasing the contact forces and fracture energy. The results showed that the in-situ synthesized iron boride phases affect the impact properties of the Fe/B4C composites.


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