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Polymer supported analogues of halogeno-sulfonamides. Preparation and applications in synthetic organic chemistry
226 synthesized by polymerization of amino acid N-carboxyanhydrides (NCAs) with amino methylated polystyrene beads. The reactions were carded out at room temperature in a triphase system with toluene, water, polymeric catalyst, and oxidant (H202-NaOH). Separation of the polymer-supported catalyst has been remarkably improved in this system, and they could be reused without a significant loss of activity. 1 S. Julia, J. Guixer, J. Masana, J. Rocas, S. Colorma, R. Annuziata, H. Molinari J. Chem. Soc., Perkin Trans. 1, (1982) 1317. Published in J. Org. Chem., 55 (1990) 6047.
Polymer Supported Analogues of Halogeno-Sulfonamides. Preparation and Applications in Synthetic Organic Chemistry M . M . S a l u n k h e , R.B. M a n e
a n d A.S. K a n a d e ,
Department of Chemistry, Shivaji University,
Kolhapur - 416 004, lndia Crosslinked polymer-supported analogous of halogeno-sulfonamides were prepared and developed as a new class of recyclable solid phase oxidizing and halogenating reagents. The preparation of these new reagents involved a three step polymer-analoguous reaction starting from styrene-divinyl benzene crosslinked polymer which is depicted in the scheme below. The active halogen content of the polymeric reagent is determined by iodometry. In these macromolecular organic reagents, the halogen atoms are at the + 1 state of oxidation and they display a halogenating power similar to those present in low molecular hypohalites. These reagents were found to oxidize primary and secondary alcohols to the corresponding carbonyl compounds in high yields. They were also found to be suitable for the halogenation of carbonyl compounds and addition reaction of a,fl-unsaturated acids. Bromo-sulfonamide polymeric reagent gave better yields as compared to a chloro-sulfonamide polymeric reagent. The spent polymeric reagent after the oxidation or halogenation step can be easily removed by filtration and can be regenerated many times in a single step without any loss of capacity. The physical nature, filterability and swelling characteristics were found to be retained under these recycling conditions.
~ ~ S ~ - f f ~C2I ) (P(, ~~/ ~ (•)•CI.So2.0H.
NH 3 S°2cl aqueous" ~ J
So2.N-CI.X"Na°X C ~ ) - - ~ So2.NH2,J (3)
Q
(2)
(3) =X= Br (3)b= X = C[ To be published in Eur. Polym. J., 27 (1991).
Synthesis and Properties of Polynucleotide Recognition Molecules R . L . Letsinger, R . H . AIuI, F. F a r o o q u i , P . M . J u n g , O.B. K i n s t l e r , Z. S k r z y p c z y n s k i a n d Z. Z h a n g , Department of Chemistry and Department of Biochemistry, Molecular Biology and Cell
Physiology, Northwestern University, Evanston, 1L 60208, USA Solid support synthetic chemistry provides convenient access to a variety of polymers related to oligonucleotides. Examples are given to illustrate: (1) applications of controlled pore glass supports in the synthesis of oligonucleotide analogues bearing modifications at phosphorus, at a ribose ring, and at a heterocyclic base group; and (2) the use of structural modifications in altering and controlling properties (e. g., hybridization, conformation, phase organization,
Polymer Supported Analogues of Halogeno-Sulfonamides. Preparation and Applications in Synthetic Organic Chemistry M . M . S a l u n k h e , R.B. M a n e
a n d A.S. K a n a d e ,
Department of Chemistry, Shivaji University,
Kolhapur - 416 004, lndia Crosslinked polymer-supported analogous of halogeno-sulfonamides were prepared and developed as a new class of recyclable solid phase oxidizing and halogenating reagents. The preparation of these new reagents involved a three step polymer-analoguous reaction starting from styrene-divinyl benzene crosslinked polymer which is depicted in the scheme below. The active halogen content of the polymeric reagent is determined by iodometry. In these macromolecular organic reagents, the halogen atoms are at the + 1 state of oxidation and they display a halogenating power similar to those present in low molecular hypohalites. These reagents were found to oxidize primary and secondary alcohols to the corresponding carbonyl compounds in high yields. They were also found to be suitable for the halogenation of carbonyl compounds and addition reaction of a,fl-unsaturated acids. Bromo-sulfonamide polymeric reagent gave better yields as compared to a chloro-sulfonamide polymeric reagent. The spent polymeric reagent after the oxidation or halogenation step can be easily removed by filtration and can be regenerated many times in a single step without any loss of capacity. The physical nature, filterability and swelling characteristics were found to be retained under these recycling conditions.
~ ~ S ~ - f f ~C2I ) (P(, ~~/ ~ (•)•CI.So2.0H.
NH 3 S°2cl aqueous" ~ J
So2.N-CI.X"Na°X C ~ ) - - ~ So2.NH2,J (3)
Q
(2)
(3) =X= Br (3)b= X = C[ To be published in Eur. Polym. J., 27 (1991).
Synthesis and Properties of Polynucleotide Recognition Molecules R . L . Letsinger, R . H . AIuI, F. F a r o o q u i , P . M . J u n g , O.B. K i n s t l e r , Z. S k r z y p c z y n s k i a n d Z. Z h a n g , Department of Chemistry and Department of Biochemistry, Molecular Biology and Cell
Physiology, Northwestern University, Evanston, 1L 60208, USA Solid support synthetic chemistry provides convenient access to a variety of polymers related to oligonucleotides. Examples are given to illustrate: (1) applications of controlled pore glass supports in the synthesis of oligonucleotide analogues bearing modifications at phosphorus, at a ribose ring, and at a heterocyclic base group; and (2) the use of structural modifications in altering and controlling properties (e. g., hybridization, conformation, phase organization,