A NEW PROCEDURE FOR THE SELECTIVE α-OXYALKYLATION OF HETEROAROMATIC BASES BY CYCLIC ETHERS AND HYDROGEN PEROXIDE

Direct Cα-heteroarylation of structurally diverse ethers via a mild N-hydroxysuccinimide mediated cross-dehydrogenative coupling reaction

An important challenge in the Cα-heteroarylation of ethers is the requirement of a large excess amount of ethers (that are used as solvents in many cases) to achieve effective transformations. This drawback has significantly restricted the Cα-heteroarylation of ethers to the use of simple and easily accessible ether substrates. To overcome this limitation, a new, efficient, N-hydroxysuccinimide (NHS) mediated, mild and metal-free CDC strategy for the direct Cα-heteroarylation of diverse ethers has been developed. Different to our previous benzaldehyde mediated photoredox Cα-heteroarylation, we have identified NHS as a new and efficient mediator without using light. A distinct non-photoredox engaged hydrogen-atom-transfer (HAT) mechanism that used a nitrogen-centered radical cation produced from NHS is initially revealed. Notably, only 5-10 equivalents of ethers as coupling partners are used, which allows for structurally diverse and complex ethers to engage in this process, to create highly medicinally relevant Cα-heteroarylated ethers. Furthermore, more structurally diverse heterocyclics can serve as reactants for this process.

Metal free C–H functionalization of diazines and related heteroarenes with organoboron species and its application in the synthesis of a CDK inhibitor, meriolin 1

Here, we report a metal-free cross-coupling reaction of diazines and related heteroarenes with organoboron species.

Cross-dehydrogenative coupling of α-C(sp3)–H of ethers/alkanes with C(sp2)–H of heteroarenes under metal-free conditions

A metal-free cross-dehydrogenative coupling method between α-oxyalkyl/alkyl radicals and electron deficient heteroarenes is reported.