A new ylide-initiated tandem cyclization reaction based on γ-dialkylation of allylic ylides has been realized, delivering a series of [3.3.0] oxa-bicyclic dienes in high yields with perfect diastereoselectivity.

The oxygen isotope ratio of dissolved inorganic phosphate (δ(18)Op) represents a novel and potentially powerful stable isotope tracer for biogeochemical research. Analysis of δ(18)Op may offer new insights into the relative importance of different sources of phosphorus within natural ecosystems. Due to the isotope fractionations that occur alongside the metabolism of phosphorus, δ(18)Op could a...

New oligomers or polymers are prepared by polymerization of arsonium ylides in the presence of boron compounds.

14 The elemental (C, N and P) and isotopic (δ 13 C, δ 15 N) content of leaves of the seagrasses 15 Thalassia testudinum, Halodule wrightii, and Syringodium filiforme were measured across a 16 10,000 km 2 survey of the seagrass communities of South Florida in 1999 and 2000. Trends at 17 local and broad spatial scales were compared to examine interspecific variation in the seagrass 18 characteris...

BACKGROUND AND OBJECTIVES Higher morning serum phosphorus has been associated with cardiovascular disease (CVD) in patients with or without CKD. In patients with CKD and a phosphorous level >4.6 mg/dl, the Kidney Disease Improving Global Outcomes guidelines recommend dietary phosphorus restriction. However, whether phosphorus restriction influences serum phosphorus concentrations and whether di...

The phosphine-catalyzed [3 + 2]-cycloaddition of 5-methylenehydantoins 4 with the ylides 5, derived from addition of tributylphosphine to the 2-butynoic acid derivatives, 6a-d, gives spiro-heterocyclic products. The camphor sultam derivative 6b gives optically active products. Noteable was that the ylides derived from ethyl 2-butynoate and the 3-(2-butynoyl)-1,3-oxazolidin-2-one derivatives 6c ...

A novel catalytic system based on covalently modified DNA is described. This catalyst promotes 1,3-dipolar reactions between azomethine ylides and maleimides. The catalytic system is based on the distortion of the double helix of DNA by means of the formation of Pt(ii) adducts with guanine units. This distortion, similar to that generated in the interaction of DNA with platinum chemotherapeutic...

The use of ylides of P, N, As or S as ligands toward transition metals is still a very active research area in organometallic chemistry. This fact is mainly due to the nucleophilic character of the ylides and to their particular bonding properties and coordination modes. They can behave as monodentate or bidentate –chelate or bridging– species, they can be used as chiral auxiliary reagents, the...

An organocatalytic strategy for the synthesis of tetrasubstituted pyrrolidines with monoactivated azomethine ylides in high enantiomeric excess and excellent exo/endo selectivity is presented. The key to success is the intramolecular activation via hydrogen bonding through an o-hydroxy group, which allows the dipolar cycloaddition to take place in the presence of azomethine ylides bearing only ...