Copper-Catalyzed Aza-Benzyl Transfer Michael Addition via C-C Bond Cleavage.

A non-noble Cu-catalyzed transfer aza-benzyl Michael addition via the C-C bond cleavage of aza-benzyl alcohols has been disclosed. The unstrained C(sp3)-C(sp3) bond of an alcohol was selectively cleaved. This aza-benzyl transfer strategy provides a selective and environmentally benign approach for the C-alkylation of α,ß-unsaturated carbonyl compounds that employs readily available alcohols as carbon nucleophiles and is characterized by a wide range of substrates and good to excellent yields.

Alkynyl Borrowing: Silver-Catalyzed Amination of Secondary Propargylic Alcohols via C(sp3)-C(sp) Bond Cleavage.

The silver-catalyzed alkynyl borrowing amination of secondary propargyl alcohols via C(sp3)-C(sp) bond cleavage has been developed. This new strategy was based on the ß-alkynyl elimination of propargyl alcohols and alkynyl as the borrowing subject. This alkynyl borrowing amination featured high atom economy, wide functional group tolerance, and high efficiency.

Sulfonylation of Propargyl Alcohols with Sulfinamides for the Synthesis of Allenyl Sulfones.

A regio- and chemoselective sulfonylation of propargyl alcohols with sulfinamides in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) was developed. It provided straightforward and mild access to multi-substituted allenyl sulfones by using sulfinamides as the sulfonyl sources. This transformation was promoted by HFIP and did not require any catalysts or oxidants, which allowed for the successful conversion of various tertiary and secondary propargyl alcohols into allenyl sulfones in high yields.

Synthesis of 1,2,4,5-tetra-substituted benzenes via copper-catalyzed dimerization of γ,δ-unsaturated ketones.

An efficient cyclization for the synthesis of 1,2,4,5-tetra-substituted benzenes via copper catalyzed dimerization of γ,δ-unsaturated ketones has been described. This one-pot procedure employs the γ,δ-unsaturated ketones as the sole substrate with multiple C-C bond formation. This protocol features broad substrate scope and provides a facile and robust method to construct polysubstituted benzene derivatives under mild conditions.

Ruthenium-Catalyzed 1,3-Aryl Redox Isomerization of Allylic Alcohols.

The isomerization of allylic alcohols to the corresponding carbonyl compounds is a well-established reaction in organic synthesis. However, 1,3-carbon migration is a quite challenging field, and thus transformation has remained elusive until now. Herein, we present the ruthenium-catalyzed intramolecular 1,3-aryl migrative isomerization, which provides a mild and environmentally friendly method to synthesize various ketones with high step- and atom-economy and broad substrate scope. Meanwhile, the Ru(III)-catalyzed C(sp3)-C(aryl) bond cleavage of unactivated allylic alcohols may serve as a heuristic paradigm for transition-metal-catalyzed C-C activation.

Silver-Catalyzed 1,3-Aza-Benzyl Migration of Allyl Alcohol.

Carbon migration of alkenyl alcohols has been recognized as an increasingly viable methodology in organic synthesis. Herein, we disclose a silver-catalyzed 1,3-aza-benzyl migration of allyl alcohols by utilizing chelation-assisted selective cleavage of an unstrained C(sp3)-C(sp3) bond. This approach provides an available, efficient, high atom-economic, and environmentally benign procedure, leading to alkylation products with broad substrate scopes and excellent yields. The migration proceeds via a one-pot, two-step process involving a free-state alkyl metal species.

1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP)-Assisted Catalyst-Free Sulfonation of Allylic Alcohols with Sulfinyl Amides.

A highly regioselective and catalyst-free sulfonation of allylic alcohols with sulfinyl amides has been realized. Such a mix-and-go procedure provides a convenient approach to synthetically various allylic sulfones under mild reaction conditions. Furthermore, this novel reaction shows ample substrate scope and outstanding functional group tolerance and could also be scaled-up. Meanwhile, it is the first example that sulfinyl amides act as a powerful sulfur nucleophile in the reactions. 1,1,1,3,3,3-Hexafluoro-2-propanol (HFIP) as a solvent plays a critical role in allylic sulfonation.