Molecular Mechanics: The Cross-conjugated Carbonyl Group in Heterocyclic Compounds. 1. Parameterisation (MM2) of the >C=O Bond

1998 ◽  
Vol 4 (12) ◽  
pp. 405-416
Author(s):  
Jean-Philippe Rameau ◽  
Germaine Robinet ◽  
Jean Devillers
RSC Advances ◽  
2020 ◽  
Vol 10 (48) ◽  
pp. 28902-28905
Author(s):  
Xue-Yan Yang ◽  
Ruizhe Wang ◽  
Lu Wang ◽  
Jianjun Li ◽  
Shuai Mao ◽  
...  

K2S2O8-promoted C–Se bond formation from the cross-coupling of C(sp3)–H bond adjacent to carbonyl group with diphenyl diselenide under metal-free conditions.


2020 ◽  
Vol 11 (SPL4) ◽  
pp. 1006-1011
Author(s):  
Khudheyer Jawad Kadem

In this work, three novel Schiff's bases subsidiaries were set up from Ethylene Diamine Tetra Acetic corrosive Derivatives(K1, K2 and K3); (K1) which was blend from response of EDTA with 4-hydroxybenzaldehyde and 2,4-dintrophenyl hydrazine. (K2) which was union from response of EDTA with vinilline and 2,4-dintrophenyl hydrazine. (K3) which was amalgamation from response of EDTA with 4-aminoacetophenone and 2,4-dintrophenyl hydrazine after that combination three novel hetrocyclic compound Containing Sulfur molecule; Derivative with compounds containing carbonyl group (aldehyde or ketone) the carbonyl group of aldehyde or ketone react with primary amine to produce mine compounds (Schiff bases), Reaction of produced Schiff base compounds with mercaptoacetic acid (thioglycolic acid) to synthesized new heterocyclic compounds Compounds with heterogeneous ring are characterized by having many biological activities Which attracts the attention of researchers, and accordingly various derivatives containing sulfur were prepared for heterocyclic compounds, these prepared compounds can have inhibitory activity for some bacteria, fungi, and viruses. (M1,M2 and M3)which were union from response of (K1,K2 and K3) individually with marcaptoacetic acid. All of the Schiff’s bases derivatives and hetrocyclic compound Containing Sulphur atom were characterized and identified by spectroscopic methods ( FT-IR and 1H-NMR) spectroscopies.


Author(s):  
Alasdair Cooper ◽  
David Leonard ◽  
Sonia Bajo ◽  
Paul Burton ◽  
David Nelson

We show that the energetically-favorable coordination of aldehydes and ketones – but not esters – to nickel(0) during Suzuki-Miyaura reactions can lead either to exquisite selectivity and enhanced reactivity, or to the inhibition<br>of the reaction. Aryl halides where the C-X bond is connected to the same π-system as an aldehyde or ketone functional<br>group undergo unexpectedly rapid oxidative addition, and are selectively cross-coupled during inter- and intramolecular<br>competition reactions. When aldehydes and ketones are present elsewhere, such as in the form of exogenous additives,<br>the cross-coupling reaction is inhibited depending on how strongly the pendant carbonyl group can coordinate to nickel(0). This work advances our understanding of how common functional groups interact with nickel(0) catalysts, and presents synthetic chemists with a tool that can be used to achieve site-selectivity in functionalized molecules. <br>


2019 ◽  
Author(s):  
Alasdair Cooper ◽  
David Leonard ◽  
Sonia Bajo ◽  
Paul Burton ◽  
David Nelson

We show that the energetically-favorable coordination of aldehydes and ketones – but not esters – to nickel(0) during Suzuki-Miyaura reactions can lead either to exquisite selectivity and enhanced reactivity, or to the inhibition<br>of the reaction. Aryl halides where the C-X bond is connected to the same π-system as an aldehyde or ketone functional<br>group undergo unexpectedly rapid oxidative addition, and are selectively cross-coupled during inter- and intramolecular<br>competition reactions. When aldehydes and ketones are present elsewhere, such as in the form of exogenous additives,<br>the cross-coupling reaction is inhibited depending on how strongly the pendant carbonyl group can coordinate to nickel(0). This work advances our understanding of how common functional groups interact with nickel(0) catalysts, and presents synthetic chemists with a tool that can be used to achieve site-selectivity in functionalized molecules. <br>


2018 ◽  
Vol 15 (5) ◽  
pp. 587-602 ◽  
Author(s):  
Moustafa S. Moustafa ◽  
Saleh M. Al-Mousawi ◽  
Hesham R. El-Seedi ◽  
Mohamed H. Elnagdi

Background: Our research group has a longstanding interest in the synthesis of novel functionalized heteroaromatic compounds, and the development of new methods for this purpose. During our ongoing investigations, we recently had an instance to check the reproducibility of some published results concerning the chemistry of arylhydrazonals, enamines and other functionally substituted carbonyl compounds. This work has led to the discovery of some new rearrangements, and the revision of the structures originally assigned to several molecules. Objective: This review surveys some correction of several erroneous reports that have appeared in the literature, and presents some interesting new rearrangements discovered in the course of investigating older reports. Results: The crystallographic studies revealed that the condensation of arylhydrazonals with active methylenenitriles yields arylazoniconates rather than pyridazenones as previously reported. Additionally, phenathylthiocyanate reacts with malononitrile to afford thiazoles rather than the previously reported condensation with the carbonyl group. In another example, the reaction of phenethylmalononitrile with hydrazine yields pyrazolopyridazenes rather than phenacylpyrazol-3,5-diamine. In yet another case, several interesting Dimrothtype rearrangements were observed when malononitrile was condensed with enaminones, contradicting earlier reports. Unexpectedly, these enaminones underwent self-trimerization to yield 1,3,5-trisubstituted benzenes under certain conditions. Enaminonitriles also undergo interesting and novel Dimroth rearrangements when reacted with cyclohexanedione or dehydroacetic acid derivatives. Conclusion: We have shown that the structures of several complex heterocyclic compounds that have been reported in the literature over the last 50 years were incorrectly assigned, possibly because the authors who originally reported them were using substandard or outdated analytical equipments.


Sign in / Sign up

Export Citation Format

Share Document