Spirans. Part 15. The effect of ring size upon the regioselective oxidative coupling of heterocyclic phenols

1982 ◽  
pp. 2617 ◽  
Author(s):  
Francis M. Dean ◽  
Mohamed O. A. Orabi
Keyword(s):  
Oxidative Coupling ◽  
Ring Size

The formation and reactions of carbanionic derivatives of methyl phosphazenes

1981 ◽  
Vol 59 (17) ◽  
pp. 2654-2664 ◽  
Author(s):  
Keith D. Gallicano ◽  
Richard T. Oakley ◽  
Norman L. Paddock ◽  
Rajendra D. Sharma
Keyword(s):  
Oxidative Coupling ◽  
Electrostatic Interactions ◽  
Ring Size ◽  
Cyclic Phosphazenes ◽  
Derivatives Of

The cyclic phosphazenes N3P3Ph4Me2, N3P3Me6, and N4P4Me8 are deprotonated by alkyllithiums. The resulting carbanions react with monofunctional electrophiles to form phosphazenes carrying the groups PCH2R (R = Me, Br, I, PhC(O), COOH AsMe2, Me3M (M = Si, Ge, Sn)). Two phosphazenyl groups can be joined either by the use of a difunctional halide or by oxidative coupling of organo-copper derivatives. The formation of the carbanions, the extent of deprotonation, substituent orientation, and the dependence of reactivity on ring size, are interpreted in terms of a balance between π-electron energies and electrostatic interactions.

Ring size effect in McMurry cyclization of 1,ω-di((azulen-1-yl)-carbonyl) alkanes

2020 ◽  
Vol 65 (1) ◽  
pp. 83-88
Author(s):  
Eugenia Andreea DRAGU ◽  
◽  
Alexandru C. RAZUS ◽  
Keyword(s):  
Size Effect ◽  
Ring Size

An Unprecedented Cyano-Induced Sodium Nitrite-Catalyzed C(sp3)-H and C(sp2)-H Coupling Reaction

2018 ◽  
Vol 15 (7) ◽  
pp. 989-994 ◽  
Author(s):  
Ling Li ◽  
Bo Su ◽  
Yuxiu Liu ◽  
Qingmin Wang
Keyword(s):  
Sodium Nitrite ◽  
Oxidative Coupling ◽  
High Resolution Mass Spectrometry ◽  
Coupling Reaction ◽  
13C Nmr Spectroscopy ◽  
Coupling Reactions ◽  
Reaction Conditions ◽  
1H And 13C Nmr ◽  
Oxidative Coupling Reaction ◽  
Oxidative Coupling Reactions

Aim and Objective: During the investigation of sodium nitrite-catalyzed oxidative coupling reaction of aryls, an unprecedented C(sp2)-H and C(sp3)-H coupling of substituted 2-aryl acetonitrile was found. Materials and Methods: The structure of the coupled product was confirmed by 1H and 13C NMR spectroscopy and high-resolution mass spectrometry (HRMS), and comparison of its derivatives with known compounds. The effects of methoxy group in the benzene ring on the reaction were evaluated. Results: The optimized reaction conditions are summarized as follows: CF3SO3H/substrate = 1.5 equiv., NaNO2/substrate = 0.3 equiv., CH3CN as solvent. 2-(4-Methoxyphenyl)acetonitrile and 2-(3,4,5- trimethoxyphenyl)acetonitrile could also generate C(sp2)-H and C(sp3)-H coupling. The coupling reaction occurred as a typical radial mechanism. Conclusion: An unprecedented cyano-induced, NaNO2-catalyzed oxidative C(sp3)-H and C(sp2)-H coupling was reported. The reaction proceeded under very mild conditions, using O2 in the air as terminal oxidant. The unique oxidative manner might provide more inspiration for the development of intriguing oxidative coupling reactions.

scholarly journals Identification of the structure of the Bi promoted Pt non-oxidative coupling of methane catalyst: a nanoscale Pt3Bi intermetallic alloy

2019 ◽  
Vol 9 (6) ◽  
pp. 1349-1356 ◽  
Author(s):  
Johnny Zhu Chen ◽  
Zhenwei Wu ◽  
Xiaoben Zhang ◽  
Slgi Choi ◽  
Yang Xiao ◽  
...  
Keyword(s):  
Oxidative Coupling ◽  
Oxidative Coupling Of Methane ◽  
Intermetallic Alloy ◽  
Alloy Catalyst

Identification of a Pt3Bi nanoscale, surface intermetallic alloy catalyst for non-oxidative coupling of methane (NOCM).

l-Prolinal Dithioacetal: A Highly Effective Organocatalyst for the Direct Nitro-Michael Addition to Selected Cyclic and Aromatic Ketones

Synthesis ◽  
2019 ◽  
Vol 51 (17) ◽  
pp. 3356-3368
Author(s):  
Piotr Pomarański ◽  
Zbigniew Czarnocki
Keyword(s):  
Michael Addition ◽  
Ring Size ◽  
Cyclic Ketones ◽  
Asymmetric Syntheses ◽  
Aromatic Ketones ◽  
Ring Systems ◽  
Effective Catalyst ◽  
Acetophenone Derivatives ◽  
Highly Effective ◽  
Related Compounds

The synthesis of novel l-prolinal dithioacetal and its application as an organocatalyst for the direct Michael addition of cyclic ketones and acetophenone derivatives to trans-β-nitrostyrene and related compounds is described. The prolinal dithioacetal acts as effective catalyst in the case of cyclic ketones of different ring size, in particular five- and six-membered examples, as well as larger and smaller ring systems. High enantioselectivity and diastereoselectivity is observed for different substrates and trans-β-nitrostyrenes. Also, the first asymmetric syntheses of selected 2-methyl-4-nitro-1,3-diphenylbutan-1-one derivatives by application of the obtained organocatalyst is presented.

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