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  • (α-Aminoalkyl)phosphonic acids  (1)
  • *Bryophyta/growth & development  (1)
  • 2000-2004  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 2000 (2000), S. 281-289 
    ISSN: 1434-193X
    Keywords: Phosphorus acid amphiphiles ; (α-Aminoalkyl)phosphonic acids ; Carboxyalkyl (α-aminoalkyl)phosphonic acid monoesters ; Spiro compounds ; Pudovik reaction ; Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The addition reaction between the P-H bond of tetraoxyspirophosphoranes 1-2 and long-chain imines 3a-h (decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, and oleyl imines) occurs instantaneously at room temperature. It is diastereoselective, and quantitatively leads to the corresponding (α-aminoalkyl)spirophosphoranes 4a-h and 5e. The influence of the pentacoordinated phosphorus atom on the stereoselectivity of the Pudovik reaction might be attributed to the involvement of the rigid spirophosphoranide (PV) intermediate in the addition reaction. Selective and one-pot hydrolysis of these P-C bond spirophosphoranes readily proceeds either at room temperature in the presence of moist solvents to give the corresponding carboxyalkyl (α-aminoalkyl)phosphonic acid monoesters 6a-h and 7e, or the reaction may be carried out in the presence of 20% aqueous hydrochloric acid under reflux, to afford the free (α-aminoalkyl)phosphonic acid amphiphiles 8a-h in high yields. In contrast to their sodium salts, these single- and double-chained free and monoester phosphonic acid amphiphiles exist as zwitterions and are not soluble in water.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
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  • 2
    Publication Date: 2004-05-25
    Description: Anisotropic (direction-dependent) long-distance dispersal (LDD) by wind has been invoked to explain the strong floristic affinities shared among landmasses in the Southern Hemisphere. Its contribution has not yet been systematically tested because of the previous lack of global data on winds. We used global winds coverage from the National Aeronautics and Space Administration SeaWinds scatterometer to test whether floristic similarities of Southern Hemisphere moss, liverwort, lichen, and pteridophyte floras conform better with (i) the anisotropic LDD hypothesis, which predicts that connection by "wind highways" increases floristic similarities, or (ii) a direction-independent LDD hypothesis, which predicts that floristic similarities among sites increase with geographic proximity. We found a stronger correlation of floristic similarities with wind connectivity than with geographic proximities, which supports the idea that wind is a dispersal vehicle for many organisms in the Southern Hemisphere.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Munoz, Jesus -- Felicisimo, Angel M -- Cabezas, Francisco -- Burgaz, Ana R -- Martinez, Isabel -- New York, N.Y. -- Science. 2004 May 21;304(5674):1144-7.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Real Jardin Botanico, Plaza de Murillo 2, 28014 Madrid, Spain. jmunoz@ma-rjb.csic.es〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/15155945" target="_blank"〉PubMed〈/a〉
    Keywords: Anisotropy ; *Bryophyta/growth & development ; *Ferns/growth & development ; Geography ; *Hepatophyta/growth & development ; *Lichens/growth & development ; Statistics as Topic ; *Wind
    Print ISSN: 0036-8075
    Electronic ISSN: 1095-9203
    Topics: Biology , Chemistry and Pharmacology , Computer Science , Medicine , Natural Sciences in General , Physics
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