01223nas a2200157   4500008004100000245009100041210006900132260000800201300001800209490000700227520064400234100002500878700002500903700001800928856011900946       2006                        eng d00aSynthesis and utility of new amine/nucleobase addition products of allenylphosphonates0 aSynthesis and utility of new aminenucleobase addition products o  cSEP  a10152–101610 v623 a<p>In the reaction of allenylphosphonates with amines/nucleobases, depending on the amine and the allenylphosphonate, either Z- or E-vinylphosphonate or allylphosphonate as a single isomer with a β-amino functionality was isolated. A simple route to phosphonates with a β-NH2 group is developed by direct reaction with ammonia. In reactions with adenine, three different modes of reaction, with one of them involving an unusual cyclisation, are observed. The utility of (enamino)allyl phosphonate products thus obtained in the synthesis of (enamino)-1,3-butadienes via Horner–Wadsworth–Emmons (HWE) reaction is also demonstrated.</p>1 aSwamy, K., C. Kumara1 aBalaraman, Ekambaram1 aKumar, Satish  uhttps://library.ncl.res.in/content/synthesis-and-utility-new-aminenucleobase-addition-products-allenylphosphonates01386nas a2200193   4500008004100000245013100041210006900172260000800241300001400249490000800263520066300271100002500934700002500959700001700984700002501001700001901026700001801045856012901063       2006                        eng d00aUnusual products in the reactions of phosphorus(III) compounds with N=N, C equivalent to C or conjugated double-bonded systems0 aUnusual products in the reactions of phosphorusIII compounds wit  cNOV  a495–5010 v1183 a<p>The diversity of products in the reaction of diethyl azodicarboxylate (DEAD)/diisopropyl azodicarboxylate (DIAD) and activated acetylenes with PIII compounds bearing oxygen or nitrogen substituents is discussed. New findings that are useful in understanding the nature of intermediates involved in the Mitsunobu reaction are highlighted. X-ray structures of two new compounds (2-t-Bu-4-MeC6H3O)P (μ-N-t-Bu)2P+[(NH-t-Bu)N[(CO2]-i-Pr)(HNCO2-i-Pr)]](Cl-)(2-t-Bu-4-MeC6H3OH)(23)and [CH2(6-t-Bu-4-Me-C6H2O)2P(O)C(CO2Me)C-(CO2Me)CClNC(O)Cl] (33) are also reported. The structure of23 is close to one of the intermediates proposed in the Mitsunobu reaction.</p>1 aSwamy, K., C. Kumara1 aBalaraman, Ekambaram1 aPavan, Phani1 aKumar, N., N. Bhuvan1 aKumar, Praveen1 aKumar, Satish  uhttps://library.ncl.res.in/content/unusual-products-reactions-phosphorusiii-compounds-nn-c-equivalent-c-or-conjugated-double02140nas a2200145   4500008004100000245020800041210006900249260000800318300001700326490000700343520144000350100002501790700002501815856015401840       2007                        eng d00aConvenient chromatography-free access to enantio-pure 6,6’-di-tert-butyl-1,1’- binaphthalene-2,2’-diol- its 3,3’-dibromo, di-tert-butyl and phosphorus derivatives: utility in asymmetric synthesis0 aConvenient chromatographyfree access to enantiopure 66 ditertbut  cSEP  a 2037–20480 v183 a<p>A simple chromatography-free high-yielding synthesis of the hexane-soluble enantiopure 6,6′-di-tert-butyl-1,1′-binaphthalene-2,2′-diol 3 (6,6′-di-tert-butyl BINOL) using Friedel–Crafts reaction on 1,1′-binaphthalene-2,2′-diol 1 (BINOL) is described. The enantiomeric purity was fully maintained in the reaction. Compound 3 has been used as an entry point for the convenient chromatography-free synthesis of 3,3′,6,6′-tetra-tert-butyl BINOL 4 and 3,3′-dibromo-6,6′-di-tert-butyl BINOL 5. A straightforward route to enantiopure bisphosphites [(6,6′-R2C20H10O2)P]2[O2C20H10-6,6′-R2] [R = H 15, t-Bu 16] by simply reacting phosphorochloridite (6,6′-R2C20H10O2)PCl [R = H 20, t-Bu 6] with metallic sodium is highlighted. The identity of 15 and 16 as their selenium-oxidized products 17 and 18 (at phosphorus center) is confirmed by X-ray crystallography (17 in the enantiopure form and 18 as racemate). Various enantiopure phosphoramidites of the modified BINOL have been synthesized. It is established that even when the phosphoramidites derived from the unsusbstituted BINOL 1 fail to give an appreciable optical induction in the asymmetric reduction of acetophenone/phenacyl chloride, those derived from 3 do induce moderate chiral induction (up to 30% ee in the case for acetophenone and 43% ee in the case of phenacyl chloride), thus leaving scope for further improvement in ee for related reactions.</p>1 aBalaraman, Ekambaram1 aSwamy, K., C. Kumara  uhttps://library.ncl.res.in/content/convenient-chromatography-free-access-enantio-pure-66%E2%80%99-di-tert-butyl-11%E2%80%99-binaphthalene-22%E2%80%9901122nas a2200157   4500008004100000245010900041210006900150260000800219300001600227490000700243520051800250100002500768700001900793700002500812856012700837       2009                        eng d00aHydrophosphonylation of activated alkenes and alkynes via fluoride ion activation in ionic liquid medium0 aHydrophosphonylation of activated alkenes and alkynes via fluori  cJUL  a7603–76100 v653 a<p>A simple transition metal-free hydro/hydrothiophosphonylation of Baylis–Hillman adducts, substituted allyl bromides, allenylphosphonates and alkynes, promoted by fluoride ion in ionic liquid, is described. Clear-cut evidence for fluoride activation of the phosphite via pentacoordinate phosphorus is provided for the first time. Also, in a comparative reaction, the product obtained was different from that from the palladium catalyzed one. Structures of key products are proven by X-ray crystallography.</p>1 aBalaraman, Ekambaram1 aSrinivas, Venu1 aSwamy, K., C. Kumara  uhttps://library.ncl.res.in/content/hydrophosphonylation-activated-alkenes-and-alkynes-fluoride-ion-activation-ionic-liquid00554nas a2200157   4500008004100000245006300041210006200104260000800166300001600174490000800190100002500198700002500223700002500248700002600273856009700299       2009                        eng d00aMitsunobu and related reactions: advances and applications0 aMitsunobu and related reactions advances and applications  cAPR  a2551–26510 v1091 aSwamy, K., C. Kumara1 aKumar, N., N. Bhuvan1 aBalaraman, Ekambaram1 aKumar, K., V. P. Pava  uhttps://library.ncl.res.in/content/mitsunobu-and-related-reactions-advances-and-applications01592nas a2200181   4500008004100000245010800041210006900149260000800218300001600226490000700242520091900249100002501168700002301193700001901216700002501235700002601260856012401286       2011                        eng d00aAlkynyl and phosphonyl substituted nucleobases: a case of thermally induced conformational polymorphism0 aAlkynyl and phosphonyl substituted nucleobases a case of thermal  cAPR  a2302–23100 v113 a<p>Substituted nucleobases with alkynyl and phosphonyl groups were investigated in the context of supramolecular interactions and possible use toward synthesis of nucleoside phosphonic acids (NPAs). The adeninyl compound (adeninyl-N-9)-CH2CH2CH2CH2C≡CH exhibits conformational polymorphism as revealed by X-ray structures determined at 200 and 298 K. Interestingly, in the compound (adeninyl-N-9)-(CH2)15CH3, the long aliphatic carbon chain does not show disorder. A rather unusual bending of alkyl chain, likely due to C–H···O interactions, is observed in the case of the thymine compound (thyminyl)-CH2CH2CH2C≡CH that possesses a terminal alkyne group. The powerful hydrogen bond acceptor property of the phosphoryl oxygen (P═O) does not perturb (unless assisted by other hydrogen bonding partners) the homo base-pairing in the structures of most of the phosphonyl substituted nucleobases studied.</p>1 aSwamy, K., C. Kumara1 aAllu, Srinivasarao1 aSrinivas, Venu1 aBalaraman, Ekambaram1 aKumar, K., V. P. Pava  uhttps://library.ncl.res.in/content/alkynyl-and-phosphonyl-substituted-nucleobases-case-thermally-induced-conformational