01295nas a2200157   4500008004100000245011600041210006900157260000800226300001600234490000700250520068500257100001800942700001600960700002900976856013201005       2016                        eng d00aHighly selective direct azidation of alcohols over a heterogeneous povidone-phosphotungstic solid acid catalyst0 aHighly selective direct azidation of alcohols over a heterogeneo  cDEC  a10240-102450 v403 aA simple protocol for the selective azidation of alcohols is developed using a solid acid hybrid of a povidone and phosphotungstic acid (PVP-PWA) using azidotrimethylsilane as an azide source at room temperature. In a broad substrate scope, various activated as well as unactivated benzylic and diphenyl alcohols were treated smoothly with TMS-N-3 to selectively produce only azide products with excellent yields in a very short reaction time of 2 h. FT-IR confirmed the stability of the catalyst with retention of the Keggins structure after the reaction. Recycling experiments demonstrated the reusability of the PVP PWA (3:1) several times without losing its original activity.1 aKamble, Sumit1 aMore, Sagar1 aRode, Chandrashekhar, V.  uhttps://library.ncl.res.in/content/highly-selective-direct-azidation-alcohols-over-heterogeneous-povidone-phosphotungstic-solid01002nas a2200169   4500008004100000245011700041210006900158260000800227300001200235490000700247520036500254100001900619700001800638700001900656700002500675856013200700       2017                        eng d00aFacile one-pot synthesis of aliphatic bridged diaryloxy compounds, cyclic and crown ethers under mild conditions0 aFacile onepot synthesis of aliphatic bridged diaryloxy compounds  cJAN  a462-4700 v293 aWe report here the facile, room temperature, catalyst free, one pot synthesis of aliphatic bridged diaryloxy compounds, cyclic and crown ethers. Anhydrous potassium carbonate (K2CO3) as a mild base along with dimethyl sulfoxide generates the phenoxide ion which facilitates the nucleophilic substitution of bromoalkanes to yield the corresponding crown ethers.1 aSakate, Sachin1 aKamble, Sumit1 aChikate, Rajiv1 aRode, Chandrashekhar  uhttps://library.ncl.res.in/content/facile-one-pot-synthesis-aliphatic-bridged-diaryloxy-compounds-cyclic-and-crown-ethers-under01795nas a2200193   4500008004100000022001400041245016600055210006900221260000800290300001400298490000700312520105700319100002101376700001601397700002001413700001801433700001901451856013101470       2025                        eng d  a1144-054600aDABCO dicationic ionic solid supported polymer (DDIS@PS) mediated synthesis of diverse 2-amino-4H-chromenes and xanthenes: a cascade Knoevenagel-Michael approach0 aDABCO dicationic ionic solid supported polymer DDISPS mediated s  cFEB  a3644-36530 v493 a<p>
	This work documented the synthesis of diverse bioactive polysubstituted 2-amino-4H-chromenes using a DABCO dicationic ionic solid (DDIS) supported on Merrifield resin (DDIS@PS) as a catalyst. The catalyst is characterized by FT-IR, SEM-EDX, and TGA analysis. The resulting PS contains supported DABCO units with free tertiary nitrogen functionality on their external surface. The catalyst effectively catalyzed cascade Knoevenagel-Michael addition reactions of various aldehydes and active methylene compounds (malononitrile and phenyl sulfonyl acetonitrile) with dimedone, yielding good to excellent results in water or ethanol at room temperature or 78 degrees C. The time required for the reaction of phenyl sulfonyl malononitrile is comparatively very high compared to malononitrile. The synthesis of bis-dimedone derivatives and 1,8-dioxo-octahydro-xanthenes was also achieved in both solvents at RT and 78 degrees C, with high yields. The catalyst demonstrated greater efficiency and maintained its activity over at least five cycles.</p>
1 aRajmane, Archana1 aPatil, Nita1 aPatil, Anuradha1 aKamble, Sumit1 aKumbhar, Arjun  uhttps://library.ncl.res.in/content/dabco-dicationic-ionic-solid-supported-polymer-ddisps-mediated-synthesis-diverse-2-amino-4h