Y. Le Bigot

A Simplified Wittig Synthesis Using Solid/Liquid Transfer Processes: II - The Use Of K2CC3 for the synthesis of alkenes from aromatic and aliphatic aldehydes

Abstract Theinterest of solid-liquid transfer processes in the wittig reaction in the presence of solid sodium hydroxide shown recently (1).

Novel Synthesis of 2‐Oxo‐2H‐Benzopyrano[2,3‐d]Pyrimidines

Abstract The synthesis of novel substituted 3‐cyanoiminocoumarins and corresponding N‐ethoxycarbonyl iminocoumarins is described. The condensation of N‐ethoxycarbonyl‐3‐cyano‐7‐diethylamino iminocoumarin with amines as N‐nucleophiles yields substituted 2‐oxo‐2H‐benzopyrano‐[2,3‐d]pyrimidines having promising optical properties.

A Simplified Wittig Synthesis Using Solid/Liquid Transfer Processes

Abstract The use of a solid-liquid phase transfer process led to the selective preparation of Z-olefins (ratio Z:E=4:1) in high yields from aromatic or aliphatic aldehydes and a phosphonium salt in alkaline media (1–4). A further advantage of the method is the possible use of non anhydrous solvents.

A Convenient Synthesis Of 3-Arylcoumarins From Arylacetonitriles

Abstract The condensation of salicylaldehydes with various arylacetonitriles catalyzed by anion-exchange resins such as Amberlite IRA 900, leads to the corresponding 3-arylcoumarins in good yields and selectivity.

A Simplified Wittig Synthesis Using Solid/Liquid Transfer Processes IV - Synthesis of symmetrical and asymmetrical mono-and di-olefins from terephtalic aldehyde

Abstract Dialdehydes can give rise, through a Wittig reaction carried out in an anhydrous homogeneous medium, to the corresponding diolefins (1–3). The high reactivity of the ylides generated under these experimental conditions precludes mono olefination which therefore requires the previous protection of one of the aldehyde functions (1–3).

A Simplified Wittig Synthesis Using a Solid-Liquid Transfer Process: V - The use of Formamide as Catalyst for the Synthesis of Alkenes From Carbonyl Compounds

Abstract A new synthetic method of preparation of alkenes with good yields, using formamide as phase transfer catalyst is described. Recently we have shown that the use of hydroxides and carbonates in solid-liquid phase transfer conditions in slightly hydrated organic mixtures permits to obtain alkenes from aldehydes with very good yield and selectivity rates (1,2).

Polymer Supported Reagents: Novel Methodology for Selective and General Synthesis of Iminocoumarins

Abstract A selective synthesis of iminocoumarins 3 was accomplished, starting from salicylaldehydes 1 and nitriles 2, by the use of Amberlite IRA 900 resin as a polymeric solid support. The possibility of using various arylacetonitriles enhances the synthetic versatility of this strategy.

New Method for the Synthesis of Difuranic Diamines and Tetrafuranic Tetra-Amines

Abstract Various difuranic diamines and tetrafuranic tetra-amines are obtained with high yields using an operating protocol extremely easy to implement.

A Simplified Wittig Synthesis Using a Solid/Liquid Transfer Process. VIII - Specific Behaviour of Methyltriphenylphosphorane During Condensation with Phenolic Aldehydes

Abstract Vinylphenols are obtained in a single-step reaction using phenolic aldehydes according to easy operating conditions involving high temperature in the reaction medium. Phenolic compounds are separated by ion-exchange resins.

A Simplified Wittig Synthesis Using a Solid/Liquid Transfer Process. IX. Selectivity of the Condensation Reaction of Moderated Ylides with Aldehydes

Abstract Conjugated dienes are obtained selectively and with high yields using aldehydes of various structures. The synthesis is made in a two-phase medium, i.e solid/liquid medium.