Mono‐ and Bimetallic Alkynyl Metallocenes and Half‐Sandwich Complexes: A Simple and Versatile Synthetic Approach

Abstract

A general process for the synthesis of alkynyl mono and dimetallic metallocenes and half-sandwich complexes has been developed. This approach uses the addition of lithium derivatives of sandwich or half-sandwich complexes to arylsulfonylacetylenes. The reaction occurs in two steps (lithiation and anti-Michael addition to alkynylsulfone followed by elimination of the ArSO moiety) to form the corresponding mono- or bimetallic alkynes in clearly higher yields, simpler experimental procedures, and more environmentally benign conditions than those of the so far reported for the synthesis of this type of products. The electrochemical properties of the newly obtained complexes have also been studied.

Nature of the Nucleophilic Oxygenation Reagent Is Key to Acid-Free Gold-Catalyzed Conversion of Terminal and Internal Alkynes to 1,2-Dicarbonyls

“…Gold complexes (Ph 3 PAuNTf 2 , IPrAuNTf 2 , PicAuCl 2 ) and N -oxides 2a – e , k – o and 2h were synthesized accordingly to the published protocols. Terminal alkynes 6b , d , e , f , internal alkynes 9 , 11b – i , o , 11k , 11n , 11p , 13a , 13b ynamides 11r , s , alkynyl ether 11t , and alkynyl thioether 11u were prepared by the literature procedures. The solvents were purified using standard techniques and stored over activated 4 Å molecular sieves before use.…”

Rhodium(III)-Catalyzed C–H Alkynylation of Ferrocenes with Hypervalent Iodine Reagents

“…Ferrocenyl alkynes and their derivatives have been intensively studied in the area of advanced materials and functional molecules because of their unique electronic and structural properties . To date, the introduction of an alkynyl group on the ferrocene backbone was mainly achieved by employing a Pd-catalyzed cross-coupling reaction of ferrocenyl halides with terminal alkynes, such as the Sonogashira coupling reaction, and the addition of ferrocenyl lithium to arylsulfonylacetylenes . However, for those methods, prefunctionalization of ferrocenes and multistep synthesis are generally required.…”