It was found that the phosphoric acid derivatives of general structure 1 serve as highly effective catalysts for the direct addition of acetyl acetone to N-Boc-protected arylimines. The beneficial effects of the 3,3'-bisaryl substituents of the catalysts on the enantioselectivity are greatly appreciated, and thus 1d functions as an excellent catalyst. The Brønsted acid-catalyzed direct Mannich reactions presented herein provide an attractive way to construct beta-aminoketones under extremely mild conditions. The stereochemical course of this reaction was established through the synthesis of Boc-(S)-phenylglycine methylester. The transformation thus demonstrated is applicable to a useful method for the synthesis of various phenylglycine derivatives.

A redox neutral, highly enantioselective coupling between N-arylaminomethanes and N-sulfonyl aldimines was developed by harnessing the efficient catalysis of P-spiro chiral arylaminophosphonium barfate and a transition-metal photosensitizer under visible light irradiation. This mode of synergistic catalysis provides a powerful strategy for controlling the bond-forming processes of reactive radical intermediates.

The parasitic plantStriga hermonthicahas been causing devastating damage to the crop production in Africa. BecauseStrigarequires host-generated strigolactones to germinate, the identification of selective and potent strigolactone agonists could help control these noxious weeds. We developed a selective agonist, sphynolactone-7, a hybrid molecule originated from chemical screening, that contains two functional modules derived from a synthetic scaffold and a core component of strigolactones. Cooperative action of these modules in the activation of a high-affinity strigolactone receptor ShHTL7 allows sphynolactone-7 to provokeStrigagermination with potency in the femtomolar range. We demonstrate that sphynolactone-7 is effective for reducingStrigaparasitism without impinging on host strigolactone-related processes.

A new asymmetric entry of the 1,2-aza-Friedel-Crafts reaction catalyzed by a chiral phosphoric acid is described. The present reaction has provided an atom-economical route to furan-2-ylamine derivatives in a highly enantioselective fashion. The synthetic utility of these products was displayed by oxidative cleavage of the furan ring (aza-Achmatowicz reaction) to form a 1,4-dicarbonyl compound that could be further derivatized to a chiral gamma-butenolid.

Chiral tetraaminophosphonium salts 1 possessing the phosphorus-centered [5.5]-spirocyclic core have been designed and synthesized in a single step from l-valine-derived diamine. The three-dimensional molecular structure was successfully verified by the single-crystal X-ray diffraction analysis, which also identified a secondary interaction between the phosphonium cation and chloride ion via double hydrogen-bonding. The potential of this novel onium salt as a chiral organic molecular catalyst has been demonstrated in an application to asymmetric direct Henry reaction.

A new variant of phosphoric acid-catalyzed C-C bond forming reaction, direct alkylation of alpha-diazoester, via C-H bond cleavage is presented. The resulting products, beta-amino-alpha-diazoesters, are highly functionalized and useful synthetic precursors for various types of beta-amino acids.

Research to develop structurally discrete, chiral supramolecular catalysts for asymmetric organic transformations has met with limited success. Here, we report that a chiral tetraaminophosphonium cation, two phenols, and a phenoxide anion appear to self-assemble into a catalytically active supramolecular architecture through intermolecular hydrogen bonding. The structure of the resulting molecular assembly was determined in the solid state by means of x-ray diffraction analysis. Furthermore, in solution the complex promotes a highly stereoselective conjugate addition of acyl anion equivalents to alpha,beta-unsaturated ester surrogates with a broad substrate scope. All structural components of the catalyst cooperatively participate in the stereocontrolling event.

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