Gold‐Catalyzed Functionalization of Unactivated C(sp³)H Bonds by Hydride Transfer Facilitated by Alkynylspirocyclopropanes

Abstract

A Golden Gate: Alkynylspirocyclopropanes served as a template for the development of gold‐catalyzed hydride transfer from unactivated C(sp3)H bonds to electronically neutral alkynes. A variety of interesting carbocyclic structures can be accessed selectively with the appropriate choice of the reaction conditions. Mechanistic studies support a sequential gold‐catalyzed cleavage of CH and CC bonds.

Gold-catalyzed C(sp3)–H bond functionalization

“…In 2012, Ballesteros et al discovered an unprecedented goldcatalyzed 1,5-hydride shift process from an unreactive methylene C-H bonds to the alkyne, leading to the subsequent selective cyclization (Scheme 19). 33 The restricted geometry in 81 may facilitate the 1,5-hydride shift to the gold-activated alkyne. From the screening of reaction conditions, it was found that the products could be controlled under microwave irradiation by simply changing the gold-complex or reaction temperature.…”

Advancement in Cascade [1,n]‐Hydrogen Transfer/Cyclization: A Method for Direct Functionalization of Inactive C(sp3)H Bonds

“…In 2012, Barluenga and co‐workers elegantly demonstrated an intriguing manifold reactivity of alkynylcyclopropanes 221 that bear a spirane core (Scheme ) 58. Remarkably, a comparatively inactive non‐benzylic secondary CH bond could work as hydride donor.…”

Studies on metal charge density and band gap characteristics produced by the (nBuCp)2ZrCl2 compound and its reaction mechanism

“…When the different functional groups were introduced the cyclopentadienyl group of the compound, the effects were mainly electron effect and steric hindrance. 33 The overwhelming steric hindrance will prevent olefin insertion reaction, resulting in inactivation of catalyst. The bonding orbital of different metallocene compounds is calculated ( Fig.…”