Organocatalytic access to 3-pyridylphosphonates from vinyl phosphonates and aldehydes.

The preparation of 3-phosphorylated pyridines has remained the most challenging compared to the corresponding 2- or 4-functionalized pyridines. Herein, an unprecedented amino-organocatalyzed direct synthesis of 3-pyridylphosphonates from vinylphosphonates and aldehydes has been achieved. This allows access to a wide range of multi-substituted phosphorylated pyridines in excellent yields under transition metal-free conditions.

Recent approaches towards one-carbon homologation-functionalization of aldehydes.

One-carbon homologation-functionalization in organic synthesis is a quite challenging and difficult task in terms of atom economy, ease of reaction, selectivity and number of steps involved. Due to the reactivity associated with most classes of carbonyls, these groups have always attracted a great deal of attention from synthetic chemists to transform them into various functionalities. In this context various researchers developed new methods for one-carbon extension-functionalization of carbonyls that serve as effective synthetic methodologies and are widely used in target-oriented and natural product synthesis.

Access to enantioenriched 4-phosphorylated δ-lactones from β-phosphorylenones and enals via carbene organocatalysis.

N-heterocyclic carbene (NHC) catalyzed direct access to enantioenriched 4-phosphorylated δ-lactones from β-phosphorylenones and enals has been achieved. The sterically demanding β-phosphonate-substituted enones, having competing regiomeric reaction centres, have remained elusive so far in intermolecular cycloaddition reactions under NHC catalysis. All the products were obtained in excellent yield and enantioselectivity.

Carbene/Base-Mediated Redox Alkenylation of Isatins using β-Substituted Organoselenones and Aldehydes.

Achieving several desired transformations in a single operation remains one of the obvious goals in the synthetic organic chemistry. Herein we developed a multicomponent reaction for the preparation of alkenylated oxyindoles, bearing a quaternary alcohol-derived ester, via an NHC-catalyzed redox reaction in the presence of β-substituted vinyl selenones and aldehydes.