Continuous Flow Synthesis of Sulfur‐ and Selenium−NHC Compounds (NHC=N‐Heterocyclic Carbene). Issue 15 (11th February 2022)

• Record Type: Journal Article
• Authors: Cauwenbergh, Thibault; Scattolin, Thomas; Simoens, Andreas; Tzouras, Nikolaos V.; Stevens, Christian V.; Nolan, Steven P.
• Is Part Of: European journal of organic chemistry. Volume 2022:Issue 15(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-02-11
• Subjects: Carbenes -- Continuous flow synthesis -- Sustainable chemistry -- Thioureas and selenoureas -- Weak base route; Chemistry, Organic -- Periodicals; Organic compounds -- Synthesis -- Periodicals; Bioorganic chemistry -- Periodicals; Chemistry, Physical organic -- Periodicals; 547
• DOI: 10.1002/ejoc.202101296
• Languages: English
• ISSNs: 1434-193X

Abstract

Abstract: The first continuous flow syntheses of sulfur‐ and selenium−NHC (NHC=N‐heterocyclic carbene) adducts in unprecedented short reaction times and high yields are reported. The importance of these species in coordination chemistry or as efficient tools for determining the π‐acceptor character of NHC ligands make any improvement in their synthesis a worthy goal. Thiourea derivatives bearing both saturated and unsaturated NHCs were obtained using NEt3 as a weak base (homogeneous setup) in conjunction with a bed of elemental sulfur (S8 ). The synthetic route proving optimal for selenoureas involves the use of a simple Se/K2 CO3 heterogeneous microreactor design. Abstract : The first continuous flow syntheses of thiourea and selenourea N‐heterocyclic carbene‐based derivatives are reported. The use of homogeneous and heterogeneous weak base flow setups allows for unprecedent short reaction times (2–5 min) under mild conditions using green solvents.