177896-09-2Relevant articles and documents
Two Distinct Ag(I)- And Au(I)-Catalyzed Olefinations between α-Diazo Esters and N-Boc-Derived Imines
Kardile, Rahul Dadabhau,Liu, Rai-Shung
, p. 6452 - 6456 (2019/09/06)
Metal-catalyzed reactions between α-diazo esters and imines were well-known to yield aziridine derivatives exclusively. This work reports two new olefination reactions between N-Boc-derived (Boc = tert-Butyloxycarbonyl) imines and α-diazo esters with Ag(I) and Au(I) catalysts, respectively. Our mechanistic studies reveal that these new olefinations involve an initial attack of diazo esters on metal/imine complexes to form Mannich-addition intermediates, which subsequently afford α-aryl-β-aminoacrylates via a Roskamp reaction, or to form β-aryl-β-aminoacrylates via the formation of silver carbenes.
A General Asymmetric Formal Synthesis of Aza-Baylis–Hillman Type Products under Bifunctional Catalysis
Frías, María,Carrasco, Ana Cristina,Fraile, Alberto,Alemán, José
supporting information, p. 3117 - 3121 (2017/12/26)
A new organocatalytic strategy for the synthesis of enantioenriched aza-Baylis–Hillman type products via a frustrated vinylogous reaction is presented. This process proceeds under mild conditions with good yields, completed Z/E selectivity and excellent e
Broad Spectrum Enolate Equivalent for Catalytic Chemo-, Diastereo-, and Enantioselective Addition to N-Boc Imines
Trost, Barry M.,Hung, Chao-I
, p. 15940 - 15946 (2016/01/09)
Alkynyl ketones are attractive but challenging nucleophiles in enolate chemistry. Their susceptibility to other reactions such as Michael additions and the difficulty of controlling the enolate geometry make them difficult substrates. Mannich-type reactions, which previously have not been reported using N-carbamoyl-imines with simple ketone enolates, became our objective. In this report, we describe the first direct catalytic Mannich-type reaction between various ynones and N-Boc imines, whose stereocontrol presumably derives from catalyst control of enolate geometry. This method produces α-substituted β-amino ynones with excellent chemo-, diastereo-, and enantioselectivity. The products can be readily transformed into a broad range of molecular scaffolds upon further one-step transformations, demonstrating the utility of ynones as masked synthetic equivalents for a variety of unsymmetrically substituted acyclic ketones. In particular, alkynyl alkyl ketones resolve the long-standing problem of the inability to use the enolates of unsymmetrical dialkyl ketones lacking α-branching for regio- and stereoselective reactions.
