Practical and high stereoselective synthesis of 3-(arylmethylene)isoindolin-1-ones from 2-formylbenzoic acid

Three-component synthesis, utilization and biological activity of phosphinoyl-functionalized isoindolinones

A new method for the synthesis of 3-oxoisoindolin-1-ylphosphine oxides bearing same or different substituents on the phosphorus atom is described. The one-pot three-component reaction of 2-formylbenzoic acid, primary amines and achiral or P-stereogenic secondary phosphine oxides provided the target compounds under catalyst-free, mild conditions and for short reaction times. The deoxygenation of a 3-oxoisoindolin-1-ylphosphine oxide was also studied, and the phosphine obtained could be converted to a sulphide and to a platinum complex. The crystal structures of a selected phosphine oxide and the corresponding platinum species were investigated by X-ray diffraction analysis. The biological activity, such as in vitro cytotoxicity on different cell lines and antibacterial activity of the 3-oxoisoindolin-1-ylphosphine oxides was also investigated. Based on the IC₅₀ values obtained, several derivatives showed moderate activity against the HL-60 cell line and two compounds containing 3,5-dimethylphenyl groups on the phosphorus atom showed promising activity against Bacillus subtilis bacteria.

Synthesis of α-Aminophosphonates and Related Derivatives; the Last Decade of the Kabachnik-Fields Reaction

The Kabachnik-Fields reaction, comprising the condensation of an amine, oxo compound and a P-reagent (generally a >P(O)H species or trialkyl phosphite), still attracts interest due to the challenging synthetic procedures and the potential biological activity of the resulting α-aminophosphonic derivatives. Following the success of the first part (Molecules 2012, 17, 12821), here we summarize the synthetic developments in this field accumulated in the last decade. The procedures compiled include catalytic accomplishments as well as catalyst-free and/or solvent-free "greener" protocols. The products embrace α-aminophosphonates, α-aminophosphinates, and α-aminophosphine oxides along with different bis derivatives from the double phospha-Mannich approach. The newer developments of the aza-Pudovik reactions are also included.

A Serendipitous One-Pot Cyanation/Hydrolysis/Enamide Formation: Direct Access to 3-Methyleneisoindolin-1-ones

A direct, one-pot conversion of 2'-haloacetophenones to 3-methyleneisoindolin-1-one scaffolds using CuCN as the sole reagent without the need for moisture-free or anaerobic conditions is reported. This serendipitously discovered transformation with a broad substrate scope provides a significantly different route towards these important scaffolds. The scope of the method has also been further extended towards the synthesis of three special scaffolds, which are analogous to various bio-active drugs.

Study on the Microwave-Assisted Batch and Continuous Flow Synthesis of N-Alkyl-Isoindolin-1-One-3-Phosphonates by a Special Kabachnik-Fields Condensation

A simple and efficient microwave (MW)-assisted method was elaborated for the catalyst-free synthesis of isoindolin-1-one-3-phosphonates by the three-component condensation of 2-formylbenzoic acid, aliphatic primary amines and various dialkyl phosphites. The batch and the continuous flow reactions were optimized in respect of the temperature, the reaction time and the molar ratio of the starting materials. To evaluate the potential of MW irradiation, comparative thermal experiments were also carried out. In order to obtain “real time” information about the condensation, the special Kabachnik–Fields reaction of 2-formylbenzoic acid, butylamine and diethyl phosphite was monitored by in situ FT-IR spectroscopy. The novel title compounds could be prepared in high yields at low temperature under a short reaction time. A suitable method could also be developed for the preparation of the isoindolin-1-one-3-phosphonates at a “few g” scale by using a continuous flow MW reactor.

Synthesis of 2-Tetrazolylmethyl-isoindolin-1-ones via a One-Pot Ugi-Azide/(N-Acylation/exo-Diels-Alder)/Dehydration Process

A series of fifteen 2-tetrazolylmethyl-isoindolin-1-one linked-type bis-heterocycles were synthesized in 10-76% yields under mild conditions via a one-pot Ugi-azide/(N-acylation/exo-Diels-Alder)/dehydration process from furan-2-ylmethanamine, aldehydes, isocyanides, azidotrimethylsilane, and maleic anhydride. Density functional theory calculations were performed using the polarizable continuum model (toluene)-M06-2X-D3/6-311+G(d)//M06-2X-D3/6-31G(d) level of theory to obtain the full energy profile when investigating over eight possible pathways. An anthracene-containing analogue displayed a distribution of its highest occupied molecular orbital-lowest unoccupied molecular orbital throughout both cyclic moieties.

Multicomponent reactions: A simple and efficient route to heterocyclic phosphonates

Multicomponent reactions (MCRs) are one of the most important processes for the preparation of highly functionalized organic compounds in modern synthetic chemistry. As shown in this review, they play an important role in organophosphorus chemistry where phosphorus reagents are used as substrates for the synthesis of a wide range of phosphorylated heterocycles. In this article, an overview about multicomponent reactions used for the synthesis of heterocyclic compounds bearing a phosphonate group on the ring is given.

Photodecarboxylative Benzylations of N-Methoxyphthalimide under Batch and Continuous-Flow Conditions

A series of photodecarboxylative benzylations of N-methoxyphthalimide were successfully realised using easily accessible starting materials. The reactions proceeded smoothly and the corresponding benzylated hydroxyphthalimidines were obtained in moderate to good yields of 52–73 %. No competing photoinduced dealkoxylation of the N-methoxy group was observed. The reaction with potassium phenylacetate was subsequently investigated in an advanced continuous-flow photoreactor. The reactor allowed rapid optimization of the reaction conditions and gave the desired benzylated product in higher yield and shorter irradiation time compared with the batch process.

Expeditious synthesis of (±)-diethyl 2-alkyl- and 2-aryl-(3-oxoisoindolin-1-yl)phosphonates catalysed by OSU-6

An efficient synthesis of (±)-diethyl 2-alkyl- and 2-aryl-(3-oxoisoindolin-1-yl)phosphonates is reported via condensation of 2-carboxybenzaldehyde with an amine and triethyl phosphite using OSU-6 as the catalyst.

A Cu-catalysed synthesis of substituted 3-methyleneisoindolin-1-one

A Cu-catalysed synthesis of substituted isoindolin-1-one has been achieved via a decarboxylative alkynylation–heteroannulation path.