74630-47-0Relevant articles and documents
Asymmetric Synthesis of Dihydropyranones via Gold(I)-Catalyzed Intermolecular [4+2] Annulation of Propiolates and Alkenes
Choi, Su Yeon,Kim, Hanbyul,Shin, Seunghoon
, p. 13130 - 13134 (2018/09/21)
Intermolecular asymmetric gold catalysis involving alkyne activation presents a significant challenge due to its distinct mechanistic mode from other metals. Herein, we report a highly enantioselective synthesis of α,β-unsaturated δ-lactones from [4+2] annulation of propiolates and alkenes in upto 95 percent ee. Notably, for the desired chiral recognition, the choice of 1,1,2,2-tetrachloroethane as solvent was found to be crucial. Furthermore, an anionic surfactant (sodium dodecyl sulfate) improved the product selectivity in the divergence of the cyclopropyl gold carbene intermediate.
Copper(i)-catalysed asymmetric allylic reductions with hydrosilanes
Thanh Nguyen,Thiel, Niklas O.,Teichert, Johannes F.
supporting information, p. 11686 - 11689 (2017/11/03)
A copper(i)-catalysed asymmetric allylic reduction enables a regio- and stereoselective transfer of a hydride nucleophile in an SN2′-fashion onto allylic bromides. This transformation represents a conceptually orthogonal approach to allylic substitution reactions with carbon nucleophiles. A copper(i) complex based upon a chiral N-heterocyclic carbene (NHC) ligand allows for stereoselectivity reaching 99% ee. The catalyst enables a stereoconvergent reaction irrespective of the double bond configuration of the starting materials.
Copper-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Alkyl Fluorides and Grignard Reagents
Iwasaki, Takanori,Shimizu, Ryohei,Imanishi, Reiko,Kuniyasu, Hitoshi,Kambe, Nobuaki
, p. 9347 - 9350 (2015/08/06)
Copper complexes generated in situ from CuCl2, alkyl Grignard reagents, and 1,3-dienes play important roles as catalytic active species for the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides through C-F bond cleavage. The alkyl group is introduced to an internal carbon atom of the 1,3-diene regioselectively, thus giving rise to the branched terminal alkene product. Making the switch: A copper-hydride species, generated by the treatment of a copper salt with alkyl Grignard reagents, catalyzes the 1,2-hydroalkylation of 1,3-dienes by alkyl fluorides and Grignard reagents. The alkyl group of the alkyl fluoride is selectively introduced to an internal carbon atom of the 1,3-diene and the Grignard reagent acts as hydride source to give the branched terminal alkene, even in the presence of alkenes and alkynes.
