N,N-Dialkyl-N′-Chlorosulfonyl Chloroformamidines in Heterocyclic Synthesis. Part XV. Some Unexpected Reactions with Anilines

2018 ◽  
Vol 71 (8) ◽  
pp. 610
Author(s):  
Dylan Innes ◽  
Michael V. Perkins ◽  
Andris J. Liepa ◽  
Craig L. Francis
Keyword(s):  
Nucleophilic Substitution ◽  
Membered Ring ◽  
Heterocyclic Synthesis ◽  
Screening Programs ◽  
Bioactive Molecule ◽  
Sterically Hindered

N,N-Dimethyl-N′-chlorosulfonyl chloroformamidine 1a underwent reactions with various anilines. In addition to the benzo[e][1,2,4]thiadiazine dioxides 8, from 1,3-NCC bis-nucleophilic substitution and bis-anilino adducts 9, some unexpected products were formed, particularly when sterically hindered or electron-poor anilines were used. In these cases, products such as the [1,3,2,4,6]dithiatriazine 1,1,3,3-tetraoxides 17 and, on occasion, N,N,5-trimethyl-4-(arylimino)-4,5-dihydro-[1,3,5]triazin-2-amines 14 were produced in significant yields. Reaction of dichloride 1a with 3-bromoaniline afforded the unusual eight-membered-ring product 2,6-bis(3-bromophenyl)-3,7-bis(dimethylamino)-2H,6H-[1,5,2,4,6,8]dithiatetrazocine 1,1,5,5-tetraoxide 28, in addition to the dithiatriazine tetraoxide 17k. These uncommon heterocyclic structures are of interest for bioactive molecule discovery screening programs.

Nucleophilic Substitution Reactions of Tetrabutylammonium aci-Nitronates with p-Substituted Nitrobenzenes

1979 ◽  
Vol 32 (11) ◽  
pp. 2413 ◽  
Author(s):  
RK Norris ◽  
D Randles
Keyword(s):  
Dimethyl Sulfoxide ◽  
Nucleophilic Substitution ◽  
Lithium Salts ◽  
Methyl Groups ◽  
The Novel ◽  
Substitution Reactions ◽  
Nucleophilic Substitution Reactions ◽  
Sterically Hindered

The reactions of tetrabutylammonium aci-nitronates with p-dinitrobenzene in dimethyl sulfoxide, benzene or acetone proceed far more rapidly than the reactions of the corresponding lithium salts and give, in unhindered cases, good yields of C-arylates, e.g. p-(1-methyl-1-nitroethyl)nitrobenzene (in 73-89% yields) and p-nitro(l,3,3-trimethyl-1-nitrobuty1)benene (in 70% yield). With more sterically hindered nitronates, O-arylation increases, giving phenols and ketoxime O-p-nitrophenyl ethers, presumably derived from the novel, intermediate p-nitrophenyl aci-nitronate esters. aci-Nitronate ions with more than two β-methyl groups gave no C-arylation. Similar results were obtained with p-fluoronitrobenzene and p-nitrobenzonitrile, A mechanism for the conversion of the intermediate aci-nitronate esters into the ketoxime ethers is proposed.

scholarly journals Palladium-Catalysed Coupling Reactions En Route to Molecular Machines: Sterically Hindered Indenyl and Ferrocenyl Anthracenes and Triptycenes, and Biindenyls

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1950 ◽  
Author(s):  
Michael J. McGlinchey ◽  
Kirill Nikitin
Keyword(s):  
Time Scale ◽  
Molecular Machines ◽  
Suzuki Coupling ◽  
Membered Ring ◽  
Coupling Reactions ◽  
Rotation Barrier ◽  
Sterically Hindered ◽  
Molecular Brake

Pd-catalysed Stille and Suzuki cross-couplings were used to prepare 9-(3-indenyl)-, 6, and 9-(2-indenyl)-anthracene, 7; addition of benzyne led to the 9-Indenyl-triptycenes, 8 and 9. In 6, [4 + 2] addition also occurred to the indenyl substituent. Reaction of 6 through 9 with Cr(CO)6 or Re2(CO)10 gave their M(CO)3 derivatives, where the Cr or Re was complexed to a six- or five-membered ring, respectively. In the 9-(2-indenyl)triptycene complexes, slowed rotation of the paddlewheel on the NMR time-scale was apparent in the η5-Re(CO)3 case and, when the η6-Cr(CO)3 was deprotonated, the resulting haptotropic shift of the metal tripod onto the five-membered ring also blocked paddlewheel rotation, thus functioning as an organometallic molecular brake. Suzuki coupling of ferrocenylboronic acid to mono- or dibromoanthracene yielded the ferrocenyl anthracenes en route to the corresponding triptycenes in which stepwise hindered rotations of the ferrocenyl groups behaved like molecular dials. CuCl2-mediated coupling of methyl- and phenyl-indenes yielded their rac and meso 2,2′-biindenyls; surprisingly, however, the apparently sterically crowded rac 2,2′-Bis(9-triptycyl)biindenyl functioned as a freely rotating set of molecular gears. The predicted high rotation barrier in 9-phenylanthracene was experimentally validated via the Pd-catalysed syntheses of di(3-fluorophenyl)anthracene and 9-(1-naphthyl)-10-phenylanthracene.

scholarly journals Unexpected fragmentation of bis(triarylstannanethiocarbonyl)disulfides, formation and X-ray structure of triarylstannyl triarylstannanecarbodithioates

2015 ◽  
Vol 3 (1) ◽  
pp. 53-59 ◽  
Author(s):  
Ihor Kulai ◽  
Oleksii Brusylovets ◽  
Nathalie Saffon ◽  
Zoia Voitenko ◽  
Stéphane Mazières ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Nucleophilic Substitution ◽  
Sulfur Atom ◽  
Driving Force ◽  
Molecular Iodine ◽  
Membered Ring ◽  
X Ray Diffraction ◽  
X Ray ◽  
Intramolecular Nucleophilic Substitution ◽  
Transition Complex

The synthesis of bis(triarylstannanethiocarbonyl)disulfides was attempted by oxidation of lithium triaryl stannane carbodithioates with molecular iodine. Unexpectedly, the desired compounds are highly unstable and undergo subsequent fragmentation giving triarylstannyl triarylstannanecarbodithioates. The proposed mechanism for this transformation assumes intramolecular nucleophilic substitution with formation of six-membered ring transition complex, stabilized by interaction between tin and thiocarbonyl sulfur atom. Obtained compounds were identified by mass-spectrometry and NMR spectroscopies, and their structures were analyzed by X-ray diffraction. These molecules show the existence of intramolecular non-bonding interactions between the sulfur atoms of the thiocarbonyl moieties and tin atoms. These interactions reflect the tin - sulfur affinity and are the main driving force in the fragmen tation of bis(triphenylstannanethiocarbonyl)disulfides.

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