Herein, we report the stereospecific Sonogashira coupling of a chiral α-bromocarboxamide possessing a tert-alkyl moiety and an alkyne; this reaction produces a chiral tert-alkylated alkyne in a stereoretentive manner. In this reaction, both the CuBr/bathophen catalyst system and carboxamide directing group are essential for achieving the high enantiospecificities of the couplings. Mechanistic studies of this reaction revealed that the alkynyl copper species is the key intermediate that coordinates to the carboxamide group of chiral α-bromocarboxamide.

Herein, we report a copper‐catalyzed stereospecific fluorination involving CsF and α‐bromocarboxamides as tertiary alkyl sources that, unlike traditional stereospecific routes involving stereoinversive SN2 reactions, proceeds with retention of stereochemistry. The developed stereospecific Cu‐catalyzed reaction is among the most efficient methods for synthesizing fluorinated molecules that possess highly congested stereogenic carbon centers. Mechanistic studies revealed that the combined reactivity of CuF2 and Cs salt is essential for completing the catalytic cycle. Our catalytic system underwent fluorination exclusively with tertiary alkyl bromides and did not react with primary alkyl bromides, indicating that this stereospecific fluorination methodology is suitable for synthesizing fluorinated building blocks possessing stereo‐defined F‐containing tertiary carbon stereogenic center.

Herein, we report a copper‐catalyzed stereospecific fluorination involving CsF and α‐bromocarboxamides as tertiary alkyl sources that, unlike traditional stereospecific routes involving stereoinversive SN2 reactions, proceeds with retention of stereochemistry. The developed stereospecific Cu‐catalyzed reaction is among the most efficient methods for synthesizing fluorinated molecules that possess highly congested stereogenic carbon centers. Mechanistic studies revealed that the combined reactivity of CuF2 and Cs salt is essential for completing the catalytic cycle. Our catalytic system underwent fluorination exclusively with tertiary alkyl bromides and did not react with primary alkyl bromides, indicating that this stereospecific fluorination methodology is suitable for synthesizing fluorinated building blocks possessing stereo‐defined F‐containing tertiary carbon stereogenic center.