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.
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.
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.
The synthesis of β,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.
A protocol for the stereocontrolled synthesis of (E)- and (Z)-β,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.
The synthesis of α-aryl, α-alkenyl, and α-alkynyl esters and amides has been extensively investigated over the past decade because of the prevalence of these substructures within the cores of ...molecules of biological instance, namely non-steroidal anti-inflammatory drugs (NSAIDs) and analgesics. New methods were developed that employ potassium organotrifluoroborate salts to overcome the drawbacks of previously reported approaches, such as lack of functional group compatibility and the necessity for an organometallic species that must be formed under low temperature, inert conditions. Optimization was carried out to determine ideal catalysts, ligands, bases, and solvents for each of the desired transformations, leading to the development of conditions for the cross-coupling of 2-chloroacetates and 2-chloroacetamides with aryl-, heteroaryl-, alkenyl-, and alkynyltrifluoroborates. The developed methods boast enhanced functional group compatibility and expand the scope of the electrophilic components compared to previous protocols. Significant interest has recently emerged in the synthesis of sp2-sp3 bonds involving non-aromatic heterocyclic structures. Interestingly, while sp2-sp3 coupling methods are known, many of the existing protocols are either completely ineffective or extremely low-yielding for secondary alkyl substrates containing heteroatoms. Conditions were developed that allowed a variety of substituted aryl and heteroaryl bromides to be cross-coupled reductively with piperidinyl, tetrahydropyranyl, pyrrolidinyl, tetrahydrofuranyl, azetidinyl, and oxetanyl bromides. The developed method utilizes bench-stable components under conditions that are tolerant of numerous functional groups, which is compatible with late-stage incorporation of saturated heterocyclic structures into larger molecules of interest. The reductive protocol was expanded to allow alkyl tosylates of nonaromatic heterocyclic systems to participate as coupling partners with aryl and heteroaryl bromides. This development allows the use of bench stable, crystalline solids that can be prepared from inexpensive, commercially available alcohols. 2,1-Borazaronaphthalenes have received a significant amount of attention because of their potentially impactful properties in the fields of pharmaceuticals and materials science. Based on conditions established for the reductive coupling of non-aromatic heterocyclic bromides with aryl bromides, the cross-coupling of non-aromatic heterocyclic halides with 2,1-borazaronaphthalenes was explored. Conditions were developed that allow reductive cross-coupling of alkyl iodides with a variety of 3- bromo-2,1-borazaronaphthalenes. This method provides a valuable, direct route to alkylated, functionalized azaborine systems.
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