Alkylgold complexes by the intramolecular aminoauration of unactivated alkenes

Abstract

Alkylgold(I) complexes were formed from the gold(I)-promoted intramolecular addition of various amine nucleophiles to alkenes. These experiments provide the first direct experimental evidence for the elementary step of gold-promoted nucleophilic addition to an alkene. Deuterium-labeling studies and X-ray crystal structures provide support for a mechanism involving anti-addition of the nucleophile to a gold-activated alkene, which is verified by DFT analysis of the mechanism. Ligand studies indicate that the rate of aminoauration can be drastically increased by use of electron-poor arylphosphines, which are also shown to be favored in ligand exchange experiments. Attempts at protodeauration lead only to recovery of the starting olefins, though the gold can be removed under reducing conditions to provide the purported hydroamination products.

AuI/AuIII Catalysis: An Alternative Approach for CC Oxidative Coupling

“…The independently isolated alkylgold(I) complex 57 [48] does not lead to the cross-coupled product when treated with Selectfluor and phenylboronic acid in the absence of alkene. This result implies that oxidation of gold(I) to goldA C H T U N G T R E N N U N G (III) must precede cyclization, affording the alkylgold-A C H T U N G T R E N N U N G (III) complex 58.…”

Flexible Gold‐Catalyzed Regioselective Oxidative Difunctionalization of Unactivated Alkenes

“…[25] Ring opening in the presence of an external nucleophile would afford compounds IV, in line with the relative configurations reported in Scheme 2. To test this hypothesis, intermediate V-d 1 [19] was prepared and submitted to the reaction conditions affording trans-2 b-d 1 and (E)-1 b-d 1 in a 2:1 ratio (Scheme 4). [11,26] Although the transformation of V into 2 b is not direct evidence of its participation in the reactions described herein, it seems to indicate that several pathways can coexist under the given reaction conditions, thus explaining the formation of the observed products.…”

Highly Efficient and Diastereoselective Gold(I)‐Catalyzed Synthesis of Tertiary Amines from Secondary Amines and Alkynes: Substrate Scope and Mechanistic Insights

“…A similar reaction mechanism of hydroamination involving less basic nitrogen nucleophiles had previously been reported by both Toste and Ujaque. [21,22] We hypothesized that gold ( …”