Ian T. Barnish

Asymmetric synthesis of β-amino acid derivatives by Michael addition to chiral 2-aminomethylacrylates

Abstract The addition of lithium enolates to chiral aminomethylacrylates 7 and 8 proceeded with excellent diastereodifferentiation (up to 98% de) and provided an expeditious synthesis of homochiral β-aminomethylglutarates 9 and 10 , on a scale of up to 500g. The acrylates 7 and 8 , and their antipodes, should be useful synthons for the synthesis of β-amino acid derivatives.

Facile intramolecular cycloadditions of 2-(N-Acylamino)-1-thia-1,3-dienes

Abstract 2-(N-Acylamino)-1-thia-1,3-dienes, generated via acylation of readily available α,β-unsaturated thioamides, undergo regio- and stereospecific intramolecular Diels-Alder cycloaddition with unactivated olefinic and acetylenic dienophiles to yield polycyclic dihydrothiopyrans.

Generation and cycloadditions of 2-(N-Acylamino)-1-thia-1,3-dienes. Part II. Rationalization of reactivity using an FMO approach.

Abstract 2-(N-Acylamino)-1-thia-1,3-dienes undergo regiospecific and stereoselective Diels-Alder cycloaddition to electron deficient, non-activated, and electron rich alkenes to give usefully functionalised dihydrothiopyrans in good yields.

Generation and cycloadditions of 2-(N-acylamino)-1-thia-1,3-dienes

Abstract 2-(N-Acylamino)-1-thia-1,3-dienes are a new class of reactive hetero-1,3-diene which can be generated in situ via acylation of α,β-unsaturated thioamides. These systems undergo Diels-Alder cycloaddition with electron deficient, non-activated and electron rich alkenes to yield usefully functionalised dihydrothiopyrans.

Generation and cycloadditions of 2-(N-acylamino)-1-thia-1, 3-dienes. Structural investigations using NMR methods. Part I.

Abstract A method has been developed for the efficient generation of2-(N-acylamino)-1-thia-1, 3-dienes. These novel hetero-dienes, which are generated via acylation of the corresponding thioamides, undergo irreversible regio- and stereospecific Diels-Alder addition to the starting thioamides to yield 6-(N-acylamino)-3, 4-dihydro-2H-thiopyrans. The regiochemistry, relative configurations and the major solution conformations of the thiopyrans 4a-c and 10 have been determined using NMR techniques. In addition, it has been found that these systems exhibit a number of unique physical and chemical properties.