The highly enantioselective sulfa-Michael addition of alkyl thiols to unactivated β-substituted-α,β-unsaturated esters catalyzed by a bifunctional iminophosphorane (BIMP) organocatalyst is described. The low acidity of the alkyl thiol pro-nucleophiles is overcome by the high Brønsted basicity of the catalyst and the chiral scaffold/thiourea hydrogen-bond donor moiety provides the required enant...

This paper describes a novel strategy for the synthesis of 2,3,4-trisubstituted pyridines via organocatalyzed three-component reactions. A variety of pyridine derivatives are synthesized from readily available ketones with α,β-unsaturated aldehydes and ammonium acetate under a mild organocatalyst. This protocol leads to rapid N-annulation through C-C and C-N bond formation in a single operation...

The behavior of readily synthesized and even commercially available (S)-proline derivatives, was studied in the trichlorosilane-mediated reduction of ketoimines. A small library of structurally and electronically modified chiral Lewis bases was considered; such compounds were shown to promote the enantioselective reduction of different substrates in good chemical yields. In the HSiCl3 addition ...

The polymerization of octamethylcyclotetrasiloxane (D4) is investigated using several five-, six- and seven-membered N-heterocyclic carbenes (NHCs). The catalysts are delivered in situ from thermally susceptible CO2 adducts. It is demonstrated that the polymerization can be triggered from a latent state by mild heating, using the highly nucleophilic 1,3,4,5-tetramethylimidazol-2-ylidene as orga...

The Wieland–Miescher ketone, Hajos–Parrish–Eder–Sauer–Wiechert and their analogues are bicyclic diketones essential as building blocks for the synthesis of several natural bioactive molecules. For this reason, since 1971, when Hajos Parrish Eder, Sauer, Wiechert reported stereoselective these compounds promoted by L-proline, numerous methodologies organocatalysts have been studied over years wi...

Abstract A highly diastereo‐ and enantioselective Mannich reaction of α ‐acetoxy‐ β ‐keto esters with isatin imine was developed. The quinine thiourea organocatalyst smoothly promoted the asymmetric to furnish various 3‐substituted‐3‐aminooxindole derivatives bearing two adjacent tetra‐substituted stereocenters in up 93 % yield, 98 ee >20 : 1 dr . transition state structure absolute configur...

Abstract A novel enantioselective (8+3) cycloaddition between donor–acceptor cyclopropanes and heptafulvenoids catalysed by a chiral bifunctional Brønsted base is described. Importantly, the reaction, which leverages an anionic activation strategy, divergent from prototypical Lewis‐acid protocols. series of cyclopropylketones react with tropones affording desired cycloadducts in high yield enan...