Asymmetric cyclizations via a sequential Michael addition/Conia-ene reaction by combining multifunctional quaternary phosphonium salt and silver catalysis

Catalytic asymmetric Nakamura reaction by gold(I)/chiral N,Nʹ-dioxide-indium(III) synergistic catalysis

“…Indanone-derived b-ketoamide 1a and phenylacetylene 2a were selected as the model substrates to conduct our research. Firstly, several cooperative catalytic systems, which showed good ability in catalytic enantioselective Conia-ene reaction, including Pd(II)/Yb(III) dual catalyst system, Zn(II)/Yb(III) catalyst system and amine-silver, were investigated 13,16,19 . But all of them gave only trace amount of product without enantioselectivities even rising the reaction temperature to 70 °C ( Table 1, Further research showed that the reaction could possess e ciency in an absolute anaerobic condition, delivering the product 3aa in 92% yield with 60:40 e.r.…”

“…The intramolecular type, which is known as the Conia-ene reaction, generating cycloalkene derivatives, has achieved signi cant progress. Besides the welldeveloped non-enantioselective systems [6][7][8][9][10][11] , catalytic asymmetric Conia-ene reactions already be realized by synergistic hard/soft Lewis acid catalysts (e.g., Pd/Yb, Yb/Zn, Ag/La, Ag/Fe) [12][13][14][15] , Lewis basic amine/Lewis acid catalysts (e.g., Cu, Ag-based) [16][17][18][19] and Brønsted basic amine/Lewis acid catalyst (B(C 6 F 5 ) 3 /Zn/PMP) 20 . In contrast, the intermolecular reaction of 1,3-dicarbonyl compounds to unactivated 1-alkynes (Nakamura reaction) was less developed.…”

Recent Advances in Phosphonium Salt Catalysis

“…Ag 2 CO 3 was found to be a very effective catalyst for the reaction in the presence of Ph 2 PMe (Scheme 18). [35] Compounds 63 bearing both electron‐donating and ‐withdrawing groups could be well tolerated to give the products 66 in good to excellent yields (up to 97%) and enantioselectivities (up to 93% ee).…”

Bifunctional Phosphonium Salt‐catalyzed Enantioselective [4+2] Annulation of Isoindigos with Allenes: Access to Complex Heterocycles with Centerpiece of 4H‐Pyrans

“…However, the phosphonium salt‐promoted annulation reactions are rare, despite such reaction process is a powerful and versatile tool for the enantioselective synthesis of both carbocyclic and heterocyclic compounds. To the best of our knowledge, just few examples on the creation of chiral carbocyclic systems via annulation processes under amino acid‐derived phosphonium salt catalysis were disclosed by Zhao and co‐workers . Quite recently, we developed novel dipeptide‐based bifunctional phosphonium salt catalysts that were successfully applied in enantioselective annulation reactions and constructing a kaleidoscope of chiral cyclic molecules .…”