Indrapal Singh Aidhen

Towards assembling of diarylmethine unit present in biologically important molecules, we have developed a new Weinreb Amide (WA) based building block derived from glycolic acid. The WA functionality present in this building block permits the sequential addition of various arylmagnesium bromide reagents in a controlled manner that enables assembly of a diarylmethine unit. The developed synthetic route provides easy access to important diarylethenes and α,α-diarylethylene glycols. The synthesized α,α-diarylethylene glycols provide access to synthetically important symmetrical and unsymmetrical α,α-diaryl acetaldehydes as valuable intermediates.

Towards the synthesis of symmetrical and unsymmetrical β,β-diarylacroleins for assembling diarylmethine fragments present in biologically important molecules, we have developed a new Weinreb amide (WA) based building block, derived from propiolic acid. The WA functionality present in this compound allowed the sequential addition of various arylmagnesium bromide reagents in a controlled manner. The developed methodology for the access to β,β-diarylacroleins has been utilised for the synthesis of biologically important 3-arylindanone molecules. Synthesis of both symmetrical and unsymmetrical β,β-diarylacrolein and diarylmethine fragments, have been achieved via easily accessible and hitherto unknown Weinreb Amide (WA) based building block 11. The WA functionality allowed the sequential addition of nucleophiles such as arylmagnesium bromide in a controlled manner, which has enabled the synthesis of an important 3-arylindanone molecule.

A new strategy for the synthesis of vinyl ketones has been achieved. Hitherto unknown and easily accessible, β-phenylseleno-N-methoxy-N- methylpropanamide, obtained through two simple reactions, served as a building block for convenient access to vinyl ketones. The N-methoxy-N-methyl amide moiety ensured no overaddition of the Grignard reagent and, hence, the excellent formation of β-phenylseleno ketones; oxidative work-up with hydrogen peroxide provided ready access to the vinyl ketones with concomitant loss of phenylselanol. © Georg Thieme Verlag Stuttgart · New York.