Engaging nonaromatic, heterocyclic tosylates in reductive cross-coupling with aryl and heteroaryl bromides.

A method has been developed for the introduction of nonaromatic heterocyclic structures onto aryl and heteroaryl bromides using alkyl tosylates in a reductive cross-coupling manifold. This protocol offers an improvement over previous methods by utilizing alkyl tosylate coupling partners that are bench-stable, crystalline solids that can be prepared from inexpensive, commercially available alcohols.

Reductive cross-coupling of nonaromatic, heterocyclic bromides with aryl and heteroaryl bromides.

Reductive cross-coupling allows the direct C-C bond formation between two organic halides without the need for preformation of an organometallic reagent. A method has been developed for the reductive cross-coupling of nonaromatic, heterocyclic bromides with aryl or heteroaryl bromides. The developed conditions use an air-stable Ni(II) source in the presence of a diamine ligand and a metal reductant to allow late-stage incorporation of saturated heterocyclic rings onto aryl halides in a functional-group tolerant manner.

Palladium-catalyzed α-arylation of 2-chloroacetates and 2-chloroacetamides.

A method has been developed for the Pd-catalyzed synthesis of α-(hetero)aryl esters and amides through a Suzuki-Miyaura cross-coupling reaction. This method avoids the use of strong base, does not necessitate inert or low temperature formation of reagents, and does not require the use of a large excess of organometallic reagent. Utilization of organotrifluoroborate salts as nucleophilic partners allows a variety of functional groups and heterocyclic compounds to be tolerated.

Reductive cross-coupling of 3-bromo-2,1-borazaronaphthalenes with alkyl iodides.

Conditions have been developed for the reductive cross-coupling of 3-bromo-2,1-borazaronaphthalenes with primary and secondary alkyl iodides. This method allows direct alkylation of azaborine cores, providing efficient access to functionalized isosteres of naphthalene derivatives.

Pd-catalyzed alkynylation of 2-chloroacetates and 2-chloroacetamides with potassium alkynyltrifluoroborates.

The synthesis of ß,γ-alkynyl esters and amides using air-stable potassium alkynyltrifluoroborates as nucleophilic partners in a mild Suzuki-Miyaura cross-coupling reaction has been achieved. Propargyl esters and amides were obtained in high yields using a low catalyst loading, and the substrate scope of the reaction has been significantly improved over previous methods.

Pd-catalyzed cross-coupling of potassium alkenyltrifluoroborates with 2-chloroacetates and 2-chloroacetamides.

A protocol for the stereocontrolled synthesis of (E)- and (Z)-ß,γ-unsaturated esters and amides is reported. 2-Chloroacetates as well as secondary and tertiary 2-chloroacetamides were successfully employed as electrophiles in the Suzuki-Miyaura cross-coupling reaction with potassium (E)- and (Z)-alkenyltrifluoroborates, affording the corresponding products in high yield.