Cleavage of a carbon-carbon triple bond via gold-catalyzed cascade cyclization/oxidative cleavage reactions of (Z)-enynols with molecular oxygen

Palladium-catalyzed cleavage reaction of carbon-carbon triple bond with molecular oxygen promoted by Lewis acid

A new Lewis acid promoted and palladium-catalyzed cleavage reaction of carbon-carbon triple bond with molecular oxygen was reported, in which alkyne or 1.3-diynes is split into carboxylic ester in various alcohols.

Gold(I)-Catalyzed Regioselective Cyclizations of Silyl Ketene Amides and Carbamates with Alkynes

The gold(I)-catalyzed regioselective cyclizations of silyl ketene amides or carbamates with alkynes were utilized to construct cyclopentanes or dehydro-delta-lactams.

Catalytic carbophilic activation: catalysis by platinum and gold pi acids

The ability of platinum and gold catalysts to effect powerful atom-economic transformations has led to a marked increase in their utilization. The quite remarkable correlation of their catalytic behavior with the available structural data, coordination chemistry, and organometallic reactivity patterns, including relativistic effects, allows the underlying principles of catalytic carbophilic activation by pi acids to be formulated. The spectrum of reactivity extends beyond their utility as catalytic and benign alternatives to conventional stoichiometric pi acids. The resulting reactivity profile allows this entire field of catalysis to be rationalized, and brings together the apparently disparate electrophilic metal carbene and nonclassical carbocation explanations. The advances in coupling, cycloisomerization, and structural reorganization--from the design of new transformations to the improvement to known reactions--are highlighted in this Review. The application of platinum- and gold-catalyzed transformations in natural product synthesis is also discussed.

Gold-Catalyzed Cyclization of Allene-Substituted Malonate Esters: Synthesis of β,γ-Unsaturated δ-Lactones

An efficient method for the preparation of beta,gamma-unsaturated delta-lactones has been developed. The starting materials for the synthesis of these compounds are allene-substituted malonates which undergo gold-catalyzed cyclization by means of nucleophilic attack of the ester moiety on the allene. It is worth mentioning that this is the first example where an ester group attacks as a nucleophile in a gold-catalyzed transformation of allenes.

Gold catalysis

Catalysis by gold has rapidly become a hot topic in chemistry, with a new discovery being made almost every week. Gold is equally effective as a heterogeneous or a homogeneous catalyst and in this Review we attempt to marry these two facets to demonstrate this new found and general efficacy of gold. The latest discoveries are placed within a historical context, but the main thrust is to highlight the new catalytic possibilities that gold-catalyzed reactions currently offer the synthetic chemist, in particular in redox reactions and nucleophilic additions to pi systems. Indeed gold has proved to be an effective catalyst for many reactions for which a catalyst had not been previously identified, and many new discoveries are still expected.

Pt- and Au-catalyzed oxidative cyclization of 2-ethenyl-1-(prop-2′-yn-1′-ol)benzenes to naphthyl aldehydes and ketones: catalytic oxidation of metal-alkylidene intermediates using H2O and H2O2

2-Ethenyl-1-(prop-2'-yn-1'-ol)benzenes was cyclized through catalytic oxidation with PtCl(2)/CO/H(2)O and PEt(3)AuCl/H(2)O(2); the metal-naphthylidene intermediates were identified and oxygenated with water and H(2)O(2), respectively; for the efficiency of cyclization, the Au catalytic system is superior to that of the PtCl(2)-catalysis because of its compatibility toward diverse alcohol substrates including both internal alkynes and terminal alkynes.