Discriminating non-ylidic carbon-sulfur bond cleavages of sulfonium ylides for alkylation and arylation reactions

A nickel-catalyzed carbon-sulfur bond metathesis has been developed to access high-value thioethers. 1,2-bis(dicyclohexylphosphino)ethane (dcype) is essential to promote this highly functional group tolerant reaction. Further, synthetically challenging macrocycles could be obtained in good yield in an unusual example of ring-closing metathesis which does not involve alkene bonds. In-depth organometallic studies support a reversible Ni(0)-Ni(II) pathway to product formation. Overall, this work does not only disclose a more sustainable and more functional group tolerant alternative to previous catalytic systems based on Pd, but also presents new applications and mechanistic information which are highly relevant to the further development and application of unusual single bond metathesis reactions.

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Carbon‐Sulfur Bond Constructions: From Transition‐Metal Catalysis to Sustainable Catalysis

The Chemical Record ◽

10.1002/tcr.202100133 ◽

2021 ◽

Author(s):

Pratheepkumar Annamalai ◽

Ke‐Chien Liu ◽

Satpal Singh Badsara ◽

Chin‐Fa Lee

Keyword(s):

Transition Metal ◽

Transition Metal Catalysis ◽

Metal Catalysis ◽

Sulfur Bond

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Sulfur-Mediated Reactions through Sulfonium Salts and Ylides

Synlett ◽

10.1055/a-1409-0906 ◽

2021 ◽

Author(s):

Pingfan Li

Keyword(s):

Transition Metal ◽

Rational Design ◽

Acid Catalysis ◽

Metal Catalysts ◽

Transition Metal Catalysts ◽

Bronsted Acid ◽

Proof Of Concept ◽

Sulfonium Salts ◽

Brönsted Acid ◽

Sulfonium Ylides

AbstractThis Account discusses several new reaction methods developed in our group that utilize sulfur-mediated reactions through sulfonium salts and ylides, highlighting the interplay of rational design and serendipity. Our initial goal was to convert aliphatic C–H bonds into C–C bonds site-selectively, and without the use of transition-metal catalysts. While a proof-of-concept has been achieved, this target is far from being ideally realized. The unexpected discovery of an anti-Markovnikov rearrangement and subsequent studies on difunctionalization of alkynes were much more straightforward, and eventually led to the new possibility of asymmetric N–H insertion of sulfonium ylides through Brønsted acid catalysis.1 Introduction2 Allylic/Propargylic C–H Functionalization3 Anti-Markovnikov Rearrangement4 Difunctionalization of Alkynes5 Asymmetric N–H Insertion of Sulfonium Ylides6 Conclusion

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Lewis acid / Base-free Strategy for the Synthesis of 2-Arylthio and Selenyl Benzothiazole / Thiazole and Imidazole

Heterocyclic Communications ◽

10.1515/hc-2020-0119 ◽

2021 ◽

Vol 27 (1) ◽

pp. 17-23

Author(s):

Guniganti Balakishan ◽

Gullapalli Kumaraswamy ◽

Vykunthapu Narayanarao ◽

Pagilla Shankaraiah

Keyword(s):

Lewis Acid ◽

Bond Formation ◽

Acid Base ◽

Mechanistic Pathway ◽

Wide Range ◽

Acid And Base ◽

Lewis Acid And Base ◽

Sulfur Bond

Abstract A Cu(II)-catalyzed Csp2-Se and Csp2-Sulfur bond formation was achieved with moderate to good yields without the aid of Lewis acid and base. The reaction is compatible with a wide range of heterocycles such as benzothiazole, thiazole, and imidazole. Also, this typical protocol is found to be active in thio-selenation via S-H activation. Additionally, we proposed a plausible mechanistic pathway involving Cu(III) putative intermediate.

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