The selective functionalization of non-activated C(sp3)—H bonds within alkyl chains represents one of the major challenges in synthetic organic chemistry. 1-bromoalkynes, readily available from simple starting materials, may be transformed into a library of molecularly complex and diverse compounds by means of a well-defined intramolecular C(sp3)—H bond insertion reaction, using extremely simple reaction conditions. In addition, these compounds display a C—Br bond amenable for further functionalization. A preliminary mechanistic study supports a concerted [1,5]-H shift / C—C bond formation involving a gold-stabilized vinylcation-like transition state. The most salient feature of this methodology is the ability to functionalize in a predictable way non-activated C(sp3)—H bonds without any sort of electronic, geometric, or conformational bias.
New main text document including DFT calculations and the corresponding discussion. New suplementary materials document including computational details. Updated authors list
Experimental procedures, spectroscopic data and computational details