Showing papers by "Christian V. Stevens published in 2007"
TL;DR: In this article, the 3,4-diamino-1H-isochromen-1-ones were produced continuously in moderate to good yields using in situ generated HCN.
60 citations
TL;DR: A new tandem reaction sequence has been developed for the synthesis of 2-phosphono pyrroles and it was found that the reaction proceeds by means of the "yne-then-ene" pathway.
Abstract: A new tandem reaction sequence has been developed for the synthesis of 2-phosphono pyrroles. The sequence consists of ring-closing enyne metathesis of a substituted aminophosphonate, containing a terminal alkyne and an internal alkene, in combination with in situ oxidation of the produced 3-pyrrolines using tetrachloroquinone. By analyzing the formation of the end and certain byproducts, taking into account the difference in reactivity of different substrates and carefully studying spectroscopic data, it was found that the reaction proceeds by means of the "yne-then-ene" pathway. During the initiation phase, a new ruthenium carbene is formed which continues the propagation cycle.
55 citations
TL;DR: When o-ethynylbenzyl alpha-aminophosphonates are heated under microwave conditions, a rearrangement occurs which results in the formation of phosphonylated isoindoles.
34 citations
TL;DR: In this paper, the synthesis of benzospiro-indolizidinepyrrolidinones is described by a domino atom transfer radical cyclization reaction using a copper catalyst.
20 citations
TL;DR: The grafting of an acyl chain onto the inulin backbone under different conditions led to a highly efficient synthesis of a series of inulin esters, with interesting tensioactive properties, which gave rise to the highest emulsion stabilities against coalescence.
19 citations
TL;DR: In this article, the synthesis of 5-phosphono-2-oxazolidinones and 2-imidaziridines was achieved from the corresponding 1-vinyl-2phosphonidines.
14 citations
TL;DR: The 1,4 and 1,2-addition of phosphites to α,β-unsaturated hydrazones was investigated in this paper, which yielded 3-phosphonyl-1-hydrazinoalkyl phosphonates.
Abstract: The 1,4- and 1,2-addition of phosphites to α,β-unsaturated hydrazones was investigated. When silylated phosphites and trialkyl phosphites were compared, trialkyl phosphites gave better conversions and subsequently higher yields. A variety of hydrazones were evaluated as substrate in this reaction, which yield 3-phosphonyl-1-hydrazinoalkyl phosphonates.
10 citations
TL;DR: In this paper, a new class of 4-phosphono-α-aminobisphosphonates was synthesized from a class of four-phphono-1-aza-1,3-dienes by the addition of dialkyl trimethylsilyl phosphites to these azadienes in the presence of acid.
Abstract: γ-Phosphono-α-aminobisphosphonates were synthesized from a new class of 4-phosphono-1-aza-1,3-dienes by the addition of dialkyl trimethylsilyl phosphites to these azadienes in the presence of acid. Depending on the steric demand of the group on nitrogen, double 1,2-addition or tandem 1,4−1,2-addition occurred.
10 citations
TL;DR: In this paper, the reactivity of 6-azabicyclo[3.2.1] octanes or 4-azabinicyclos[3,3.3.0]octanes was shown to be a function of the N protecting group of pyroglutamates.
9 citations
TL;DR: The synthesis of a series of analogues in which the hydroxamate moiety is incorporated in a ring structure, leaving the complexation with the enzyme up to the oxygen lone pairs instead of the free hydroxyl group.
Abstract: Fosmidomycin is a promising antimalarial compound with a novel mode of action, the inhibition of 1-deoxy- D-xylulose 5-phosphate reductoisomerase, a key enzyme in the biosynthesis of isoprenoids through the nonmevalonate pathway. This paper describes the synthesis of a series of analogues in which the hydroxamate moiety is incorporated in a ring structure, leaving the complexation with the enzyme up to the oxygen lone pairs instead of the free hydroxyl group. The antimalarial activities of the different analogues are currently under investigation.
3 citations
01 Jan 2007
TL;DR: A short general introduction combined with some historical milestones in the field of olefin metathesis is presented in this article followed by an overview of recent repre- contributions and overwhelming work invested in intelligent design and innovative synthesis in this area.
Abstract: A short general introduction combined with some historical milestones in the field of olefin metathesis is presented followed by an overview of recent repre- contributions and overwhelming work invested in intelligent design and innovative synthesis in this area. Despites of recent advances there is still a great interest in the generation of new, better performing, and more environment friendly metathesis.
TL;DR: Trialkyl phosphites were evaluated for addition reactions to α,β-unsaturated imines as discussed by the authors, and 3-phosphonyl-1-aminophosphonates, phosphonic acid analogues of glutamate, were obtained in good yields (32−90%).
Abstract: Trialkyl phosphites were evaluated for addition reactions to α,β-unsaturated imines. An acidic medium is required to allow consecutive 1,4- and 1,2-addition to occur. In this manner, 3-phosphonyl-1-aminophosphonates, phosphonic acid analogues of glutamate, are obtained in good yields (32−90%). The reaction is mainly influenced by the steric bulk of the nitrogen substituent: less steric N-substituents lead to better yields of the tandem adducts.
TL;DR: A short approach was developed towards phosphonylated benzazepines as discussed by the authors, where Aminophosphonates containing an 'yne' and an 'ene' moiety were synthesised via phosphonylation of the corresponding imines.
Abstract: A short approach was developed towards phosphonylated benzazepines. Aminophosphonates containing an 'yne' and an 'ene' moiety were synthesised via phosphonylation of the corresponding imines. The key step in the reaction sequence is a domino enyne-metathesis-cross-metathesis.
TL;DR: When o-ethynylbenzyl α-aminophosphonates are heated under microwave conditions, a rearrangement occurs which results in the formation of phosphonylated isoindoles as discussed by the authors.
Abstract: When o-ethynylbenzyl α-aminophosphonates are heated under microwave conditions, a rearrangement occurs which results in the formation of phosphonylated isoindoles. The rearrangement consists of a 5-exo-dig cyclization followed by a [1,3]-alkyl shift and finally aromatization.
TL;DR: In this article, a new tandem reaction sequence was developed for the synthesis of 2-phosphono pyrroles, which consists of ring-closing enyne metathesis of a substituted aminophosphonate, containing a terminal alkyne and an internal alkene, in combination with in situ oxidation of the produced 3-pyrrolines using tetrachloroquinone.
Abstract: A new tandem reaction sequence has been developed for the synthesis of 2-phosphono pyrroles. The sequence consists of ring-closing enyne metathesis of a substituted aminophosphonate, containing a terminal alkyne and an internal alkene, in combination with in situ oxidation of the produced 3-pyrrolines using tetrachloroquinone. By analyzing the formation of the end and certain byproducts, taking into account the difference in reactivity of different substrates and carefully studying spectroscopic data, it was found that the reaction proceeds by means of the "yne-then-ene" pathway. During the initiation phase, a new ruthenium carbene is formed which continues the propagation cycle.