scholarly journals Regioselective synthesis of heterocyclic N-sulfonyl amidines from heteroaromatic thioamides and sulfonyl azides

2020 ◽  
Vol 16 ◽  
pp. 2937-2947
Author(s):  
Vladimir Ilkin ◽  
Vera Berseneva ◽  
Tetyana Beryozkina ◽  
Tatiana Glukhareva ◽  
Lidia Dianova ◽  
...  
Keyword(s):  
Regioselective Synthesis ◽  
Dimroth Rearrangement ◽  
Sulfonyl Azides ◽  
Reliable Procedure ◽  
First Time ◽  
Heterocyclic Thioamides ◽  
Heteroaromatic Thioamides

N-Sulfonyl amidines bearing 1,2,3-triazole, isoxazole, thiazole and pyridine substituents were successfully prepared for the first time by reactions of primary, secondary and tertiary heterocyclic thioamides with alkyl- and arylsulfonyl azides. For each type of thioamides a reliable procedure to prepare N-sulfonyl amidines in good yields was found. Reactions of 1-aryl-1,2,3-triazole-4-carbothioamides with azides were shown to be accompanied with a Dimroth rearrangement to form 1-unsubstituted 5-arylamino-1,2,3-triazole-4-N-sulfonylcarbimidamides. 2,5-Dithiocarbamoylpyridine reacts with sulfonyl azides to form a pyridine bearing two sulfonyl amidine groups.

Nitroacenaphthene as a New Photocatalyst for the Synthesis of Sulfonyl Amidines

Synthesis ◽  
2019 ◽  
Vol 51 (23) ◽  
pp. 4425-4433
Author(s):  
Yong Jian ◽  
Ming Chen ◽  
Chao Yang ◽  
Wujiong Xia
Keyword(s):  
Visible Light ◽  
Small Molecule ◽  
Reaction Pathways ◽  
Visible Light Photocatalyst ◽  
Mild Conditions ◽  
Sulfonyl Azides ◽  
Site Selective ◽  
First Time

A small molecule, namely nitroacenaphthene, is reported for the first time as a recyclable visible-light photocatalyst for the construction of the C=N bond from sulfonyl azides and amines. This scalable, site-selective protocol provides a convenient way to access various sulfonyl amidines under mild conditions. Two reaction pathways are proposed, according to different transformation patterns.

Regioselective Late-Stage C-3 Functionalization of Pyrazolo[3,4-b]pyridines

Synthesis ◽  
2018 ◽  
Vol 50 (05) ◽  
pp. 998-1006 ◽  
Author(s):  
Florence Popowycz ◽  
Hubert Lavrard
Keyword(s):  
Late Stage ◽  
Pyridine Derivatives ◽  
Reliable Procedure ◽  
First Time

This contribution reports for the first time the late-stage C–H activation of pyrazolo[3,4-b]pyridine derivatives. A family of 16 molecules functionalized on the C-3 position by this methodology is demonstrated. After a careful optimization, a reliable procedure has been developed with Pd(phen)2(PF6)2 catalyst (10 mol%), affording C-3 arylated pyrazolo[3,4-b]pyridines in yields ranging from 40 to 81%.

scholarly journals Chloro- and Dichloro-methylsulfonyl Nitrenes: Spectroscopic Characterization, Photoisomerization, and Thermal Decomposition

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3312 ◽  
Author(s):  
Yang Yang ◽  
Xianxu Chu ◽  
Yan Lu ◽  
Manabu Abe ◽  
Xiaoqing Zeng
Keyword(s):  
Uv Light ◽  
Spectroscopic Characterization ◽  
Nitroso Compounds ◽  
Triplet Ground State ◽  
Sulfonyl Azides ◽  
15N Labeling ◽  
Underlying Mechanisms ◽  
First Time ◽  
State Multiplicity ◽  
Calculated Potential Energy

Chloro- and dichloro-methylsulfonyl nitrenes, CH2ClS(O)2N and CHCl2S(O)2N, have been generated from UV laser photolysis (193 and 266 nm) of the corresponding sulfonyl azides CH2ClS(O)2N3 and CHCl2S(O)2N3, respectively. Both nitrenes have been characterized with matrix-isolation IR and EPR spectroscopy in solid N2 (10 K) and glassy toluene (5 K) matrices. Triplet ground-state multiplicity of CH2ClS(O)2N (|D/hc| = 1.57 cm−1 and |E/hc| = 0.0026 cm−1) and CHCl2S(O)2N (|D/hc| = 1.56 cm−1 and |E/hc| = 0.0042 cm−1) has been confirmed. In addition, dichloromethylnitrene CHCl2N (|D/hc| = 1.57 cm−1 and |E/hc| = 0 cm−1), formed from SO2-elimination in CHCl2S(O)2N, has also been identified for the first time. Upon UV light irradiation (365 nm), the two sulfonyl nitrenes R–S(O)2N (R = CH2Cl and CHCl2) undergo concomitant 1,2-R shift to N-sulfonlyamines R–NSO2 and 1,2-oxygen shift to S-nitroso compounds R–S(O)NO, respectively. The identification of these new species with IR spectroscopy is supported by 15N labeling experiments and quantum chemical calculations at the B3LYP/6-311++G(3df,3pd) level. In contrast, the thermally-generated sulfonyl nitrenes CH2ClS(O)2N (600 K) and CHCl2S(O)2N (700 K) dissociate completely in the gas phase, and in both cases, HCN, SO2, HCl, HNSO, and CO form. Additionally, ClCN, OCCl2, HNSO2, •NSO2, and the atmospherically relevant radical •CHCl2 are also identified among the fragmentation products of CHCl2S(O)2N. The underlying mechanisms for the rearrangement and decomposition of CH2ClS(O)2N and CHCl2S(O)2N are discussed based on the experimentally-observed products and the calculated potential energy profile.

W(CO)3(Ph2PC2H4PPh2)(η2-Sc3N@Ih-C80/Sc3N@D5h-C80): regioselective synthesis and crystallographic characterization of air-stable mononuclear complexes of endohedral fullerenes

2016 ◽  
Vol 45 (29) ◽  
pp. 11606-11610 ◽  
Author(s):  
Lipiao Bao ◽  
Bin Liu ◽  
Xiaofang Li ◽  
Changwang Pan ◽  
Yunpeng Xie ◽  
...  
Keyword(s):  
Coordination Complexes ◽  
Regioselective Synthesis ◽  
Endohedral Fullerenes ◽  
Endohedral Metallofullerenes ◽  
Mononuclear Complexes ◽  
First Time

Air-stable mononuclear coordination complexes of endohedral metallofullerenes have been regioselectively synthesized and crystallographically characterized for the first time.

Regioselective synthesis of salicylates and acetophenones by formal [3+3]-cyclocondensations of 3-oxoorthoesters with 1,3-bis(trimethylsilyloxy)-1,3-butadienes

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jörg-Peter Gütlein ◽  
Mathias Lubbe ◽  
Holger Feist ◽  
Alexander Villinger ◽  
Peter Langer
Keyword(s):  
Regioselective Synthesis ◽  
First Time

AbstractA variety of 4-methoxysalicylates and related polyketide-type phenols are regioselectively prepared by formal [3+3] cyclocondensations of 1,3-bis(trimethylsilyloxy)-1,3-butadienes with 3-oxo-orthoesters. Cycloalkyl-substituted salicylates were prepared for the first time.

Ruthenium catalyzed chemo and site-selective C–H amidation of oxobenzoxazine derivatives with sulfonyl azides

2019 ◽  
Vol 43 (35) ◽  
pp. 14190-14195 ◽  
Author(s):  
Manickam Bakthadoss ◽  
Polu Vijay Kumar ◽  
Ravan Kumar ◽  
Manickam Surendar ◽  
Duddu S. Sharada
Keyword(s):  
Sulfonyl Azides ◽  
Site Selective ◽  
First Time

A novel and general protocol towards the synthesis of highly functionalized ortho-amido oxobenzoxazine frameworks via ruthenium catalyzed intermolecular C–H amidation using sulfonyl azides as amidation components has been developed for the first time.

The Regioselective Synthesis of o-Nitrobenzyl DOPA Derivatives

Synthesis ◽  
2017 ◽  
Vol 49 (12) ◽  
pp. 2691-2699 ◽  
Author(s):  
Tobias Schneider ◽  
Joshua Martin ◽  
Patrick Durkin ◽  
Vladimir Kubyshkin ◽  
Nediljko Budisa
Keyword(s):  
Synthetic Peptides ◽  
Biological Systems ◽  
New Method ◽  
Regioselective Synthesis ◽  
Non Invasive ◽  
Efficient Control ◽  
Synthetic Routes ◽  
Adhesive Proteins ◽  
First Time ◽  
Catechol Moiety

Photocaged DOPA derivatives may serve for non-invasive unmasking of the catechol fragment in biological systems. This would enable efficient control of the redox and metal-coordinating properties associated with the free catechol moiety, in particular, in biosynthetically produced adhesive proteins and synthetic peptides. Synthetic routes towards photocaged DOPA derivatives are reported herein. A new method for preparing para-alkylated DOPA starting from 3,4-dihydroxybenzaldehyde is described for the first time.

scholarly journals Copper-catalyzed olefinic C–H difluoroacetylation of enamides

2014 ◽  
Vol 50 (44) ◽  
pp. 5887-5890 ◽  
Author(s):  
Gilles Caillot ◽  
Jérémy Dufour ◽  
Marie-Charlotte Belhomme ◽  
Thomas Poisson ◽  
Laurence Grimaud ◽  
...  
Keyword(s):  
Regioselective Synthesis ◽  
First Time

An efficient copper-catalyzed method for the regioselective synthesis of β-difluoroester substituted enamides using BrCF2CO2Et is reported for the first time.

Regioselective synthesis of polycyclic sulfones via radical-induced three-component bicyclization cascades

2019 ◽  
Vol 55 (22) ◽  
pp. 3227-3230 ◽  
Author(s):  
Xiao-Yan Qin ◽  
Long He ◽  
Jing Li ◽  
Wen-Juan Hao ◽  
Shu-Jiang Tu ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Regioselective Synthesis ◽  
Internal Alkynes ◽  
First Time

New radical-triggered three-component bicyclization cascades of 2-alkynylaryldiazonium tetrafluoroborates with a sulfur dioxide surrogate DABCO·(SO2)2 and internal alkynes have been reported for the first time, leading to 49 examples of polycyclic sulfones with moderate to good yields.

Annulate lamellae in the Sertoli cells of guinea pig testis after unilateral torsion of the spermatic cord

1984 ◽  
Vol 42 ◽  
pp. 196-197
Author(s):  
J. Chakraborty ◽  
A. P. Sinha Hikim ◽  
J. S. Jhunjhunwala
Keyword(s):  
Sertoli Cells ◽  
Guinea Pigs ◽  
Spermatic Cord ◽  
Present Report ◽  
Cell Types ◽  
Annulate Lamellae ◽  
Spermatogenic Cells ◽  
Electron Microscopic ◽  
Structural Details ◽  
First Time

Although the presence of annulate lamellae was noted in many cell types, including the rat spermatogenic cells, this structure was never reported in the Sertoli cells of any rodent species. The present report is based on a part of our project on the effect of torsion of the spermatic cord to the contralateral testis. This paper describes for the first time, the fine structural details of the annulate lamellae in the Sertoli cells of damaged testis from guinea pigs.One side of the spermatic cord of each of six Hartly strain adult guinea pigs was surgically twisted (540°) under pentobarbital anesthesia (1). Four months after induction of torsion, animals were sacrificed, testes were excised and processed for the light and electron microscopic investigations. In the damaged testis, the majority of seminiferous tubule contained a layer of Sertoli cells with occasional spermatogonia (Fig. 1). Nuclei of these Sertoli cells were highly pleomorphic and contained small chromatinic clumps adjacent to the inner aspect of the nuclear envelope (Fig. 2).

Sign in / Sign up

Export Citation Format

Share Document