Gold-Catalyzed Sequential Alkyne Activation for the Synthesis of 4,6-Disubstituted Phosphorus 2-Pyrones

Abstract

Tandem gold-catalyzed addition of alkynyl phosphonic acid monoethyl esters to terminal alkynes and cyclization were developed for the synthesis of 4,6-disubstituted phosphorus 2-pyrones in one reaction vessel based on the concept of sequential alkyne activation. Alkynyl enol phosphonates were selectively obtained through the gold-catalyzed addition reaction in the presence of a catalytic amount of triethylamine. Also, gold-catalyzed cyclization of alkynyl enol phosphonates was successful in giving a variety of 4,6-disubstituted phosphorus 2-pyrones.

Rhodium-Catalyzed Oxidative Cyclization of Arylphosphonic Acid Monoethyl Esters with Alkenes: Efficient Synthesis of Benzoxaphosphole 1-Oxides

“…Although the phosphonic acid and its derivatives have been used as essential compounds in the field of organic, bioorganic, and medicinal chemistry, their application in C–H bond functionalizations catalyzed by transition metals has been scarcely investigated. , Furthermore, the structural variation of phosphonic acid derivatives would be more flexible than that of carboxylic acid derivatives by introduction of different groups to the pentavalent phosphorus atom. In this regard, we have been interested in developing an efficient synthetic method for a wide range of organophosphorus compounds with the purpose of making focused chemical libraries effective for chemical biology study and drug discovery. , …”

Cs2CO3-Promoted One-Pot Synthesis of Alkynylphosphonates, -phosphinates, and -phosphine Oxides

“…Carbon–phosphorus bond construction for the synthesis of organophosphorus compounds is a fundamental and significant research topic in both organic synthesis and industrial processes during the past decades due to their increasing importance in organic synthesis, materials, and biology. Alkynyl-phosphorus compounds including alkynyl-phosphonates, -phosphinates, and -phosphine oxides are an important class of triple bond-containing, extremely versatile chemicals in modern organic chemistry, which are widely available for the preparation of structurally sophisticated phosphorus-containing compounds via reductions, hydrations, conjugate-addition reactions, metallacycle formation, and unique cycloaddition reactions . Preparation of alkynylphosphorus compounds has aroused great interest among synthetic chemists for their important roles over the past decades, but the known highly efficient method is still rather limited.…”

Gold(I)‐Catalyzed Synthesis of Six‐Membered P,O‐Heterocycles via Hydration/Intramolecular Cyclization Cascade Reaction

“…Gold complexes have also been used to promote the synthesis of heterocyclic phosphorus compounds, which are useful in organic synthesis, medicinal chemistry, and material science. In 2013, Lee reported the gold(I)‐catalyzed sequential alkyne activation for the preparation of 4,6‐disubstituted phosphorus 2‐pyrones . At the same year, the author reported the synthesis of phosphacoumarins via a gold(I)‐catalyzed hydroarylation of aryl alkynylphosphonates .…”