01175nas a2200217 4500008004100000022001300041245015400054210007100208260000800279300001400287490000700301520036800308100001800676700002500694700002200719700001900741700002200760700002000782700002200802856013300824 2018 eng d a1359734500aTransition metal free regio-selective C–H hydroxylation of chromanones towards the synthesis of hydroxyl-chromanones using PhI(OAc)2 as the oxidant0 aTransition metal free regioselective C–H hydroxylation of chroma cFEB a2252-22550 v543 a

The chromanone scaffold is considered as a privileged structure in drug discovery. Herein, we report a highly efficient PhI(OAc)2 mediated regioselective, direct C–H hydroxylation of chromanones. This method offers easy access to substituted 6-hydroxy chromanones in moderate to good isolated yields, thus paving the way for their pharmaceutical studies.

1 aViswanadh, N.1 aGhotekar, Ganesh, S.1 aThoke, Mahesh, B.1 aVelayudham, R.1 aShaikh, Aslam, C.1 aKarthikeyan, M.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/transition-metal-free-regio-selective-c%E2%80%93h-hydroxylation-chromanones-towards-synthesis01060nas a2200229 4500008004100000022001400041245007400055210006900129260000800198300001400206490000700220520035600227653002600583653001200609653001100621653001500632653001400647100002500661700001600686700002200702856010600724 2019 eng d a0039-788100aEfficient synthesis of optically active neolignans ligraminol D and E0 aEfficient synthesis of optically active neolignans ligraminol D  cNOV a4291-42950 v513 a

Efficient syntheses of optically active neolignans ligraminol D and E were achieved in four simple steps starting from easily available chiral benzyl glycidyl ethers. The products were obtained in good overall yields and high enantioselectivities. The protocol might also be useful in the synthesis of other ligraminols or related neolignans.

10abenzyl glycidyl ether10aEpoxide10alignan10aligraminol10aMitsunobu1 aGhotekar, Ganesh, S.1 aMujahid, M.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/efficient-synthesis-optically-active-neolignans-ligraminol-d-and-e00930nas a2200181 4500008004100000022001400041245006600055210006600121260000900187300001600196490000700212520034100219100002500560700002200585700002100607700002200628856009800650 2019 eng d a1144-054600aNew enantioselective synthesis of antiobesity drug lorcaserin0 aNew enantioselective synthesis of antiobesity drug lorcaserin cNOV  a16876-168800 v433 a

A simple and efficient enantioselective synthesis of anti-obesity drug lorcaerin starting from easily accessible 3-chlorostyrene oxide has been described for the first time employing hydrolytic kinetic resolution as a source of chirality. The protocol might also be useful in the synthesis of structural variants of lorcaserin.

1 aGhotekar, Ganesh, S.1 aMore, Devidas, A.1 aNalla, Viswanadh1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/new-enantioselective-synthesis-antiobesity-drug-lorcaserin01021nas a2200169 4500008004100000022001400041245016200055210006900217260000800286300001400294490000700308520033900315100002500654700002200679700002200701856012800723 2019 eng d a0022-326300aTransition-metal-free benzannulation of tricarbonyl derivatives with arynes: access to 1,3-dinaphthol precursors for the synthesis of rhodamine dye analogues0 aTransitionmetalfree benzannulation of tricarbonyl derivatives wi cFEB a2269-22760 v843 a

Herein, we report a transition-metal-free annulation reaction of benzynes and 1,3-oxopentanedioate for the synthesis of highly functionalized naphthalene derivatives for the first time. Additionally, the representative naphthalene derivatives have been successfully transformed into the new series of rhodamine dye analogues.

1 aGhotekar, Ganesh, S.1 aShaikh, Aslam, C.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/transition-metal-free-benzannulation-tricarbonyl-derivatives-arynes-access-13-dinaphthol01193nas a2200181 4500008004100000022001400041245016800055210006900223260000900292300001400301490000700315520046600322100002500788700002500813700002200838700002200860856012900882 2020 eng d a1359-734500a1,6-Conjugate addition initiated formal [4+2] annulation of p-quinone methides with sulfonyl allenols: a unique access to spiro[5.5]undeca-1,4-dien-3-one scaffolds0 a16Conjugate addition initiated formal 42 annulation of pquinone  cMAY  a5022-50250 v563 a

An expedient one-pot synthesis of carbocyclic spiro[5.5]undeca-1,4-dien-3-ones via 1,6-conjugate addition initiated formal [4+2] annulation sequences by employing p-quinone methides and sulfonyl allenols is presented. Furthermore, this synthetic protocol tolerates a wide variety of p-quinone methides and sulfonyl allenols and affords the corresponding structurally unique spiro[5.5]undeca-1,4-dien-3-ones in good yield under mild reaction conditions.

1 aGhotekar, Ganesh, S.1 aShirsath, Sachin, R.1 aShaikh, Aslam, C.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/16-conjugate-addition-initiated-formal-42-annulation-p-quinone-methides-sulfonyl-allenols01330nas a2200193 4500008004100000022001400041245018400055210006900239260000900308300001600317490000700333520055700340100002500897700002500922700001700947700002400964700002200988856012601010 2020 eng d a0022-326300aSilver-catalyzed cascade cyclization/1,6-conjugate addition of homopropargyl sulfonamides to p-quinone methides: an approach to diverse 3-diarylmethine substituted dihydropyrroles0 aSilvercatalyzed cascade cyclization16conjugate addition of homop cDEC  a15038-150500 v853 a

A silver-catalyzed cycloisomerization/1,6-conjugate addition of homopropargyl sulfonamides to p-quinone methides to access diverse diarylmethine substituted dihydropyrroles has been disclosed. The reaction pathway involves an intramolecular cascade cyclization of homopropargyl sulfonamides to generate a highly reactive dihydropyrrole intermediate in situ followed by conjugate addition with p-quinone methides. This method provides an efficient and scalable route for the synthesis of 3-diarylmethine substituted dihydropyrroles, in one pot.

1 aShirsath, Sachin, R.1 aGhotekar, Ganesh, S.1 aBahadur, Vir1 aGonnade, Rajesh, G.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/silver-catalyzed-cascade-cyclization16-conjugate-addition-homopropargyl-sulfonamides-p01162nas a2200157 4500008004100000022001400041245010200055210006900157260000800226490000700234520056300241100002200804700002500826700002200851856013100873 2023 eng d a1861-472800aBF3.Et2O-catalyzed selective C-4 alkylation of isoquinolin1(2H)-ones employing p-quinone methides0 aBF3Et2Ocatalyzed selective C4 alkylation of isoquinolin12Hones e cSep0 v183 a

The direct C-4 alkylation of isoquinolin-1(2H)-one moiety is a challenging transformation in organic synthesis. Here we present a practical and efficient synthesis of C-4 alkylated isoquinolin-1(2H)-ones through conjugate addition of isoquinolin-1(2H)-ones to p-quinone methides for the first time. The process is facilitated by Lewis acid catalysis and this operationally straightforward, mild, metal-free and one-pot transformation provides a wide range of C-4 alkylated isoquinolin-1(2H)ones at ambient temperature in good to excellent yields.

1 aMore, Devidas, A.1 aGhotekar, Ganesh, S.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/bf3et2o-catalyzed-selective-c-4-alkylation-isoquinolin12h-ones-employing-p-quinone-methides01226nas a2200253 4500008004100000022001400041245011000055210006900165260000800234300001400242490000700256520035900263653001800622653001500640653002200655653003300677653002800710653001900738100002500757700002100782700002300803700002200826856012400848 2023 eng d a0022-326300aPalladium-catalyzed oxidative cyclization of ?-allenols in the presence of TBN: access to 3(2H)-furanones0 aPalladiumcatalyzed oxidative cyclization of allenols in the pres cAPR a4112-41220 v883 a

A new palladium-catalyzed oxidative cyclization of alpha-allenols is described. The readily accessible alpha-allenols participate in intra-molecular oxidative cyclization in the presence of TBN to grant access to multisubstituted 3(2H)-furanones, which are common motifs in several biologically important natural products and pharmaceuticals.

10aAlternatively10aconditions10acumbersome workup10aintramolecular electrophilic10amultiple reaction steps10anoted examples1 aGhotekar, Ganesh, S.1 aShinde, Ravi, A.1 aSaswade, Sagar, S.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/palladium-catalyzed-oxidative-cyclization-allenols-presence-tbn-access-32h-furanones01514nas a2200217 4500008004100000022001400041245019300055210006900248260000800317490000700325520062400332653003900956653004300995653002001038653002401058100001601082700002201098700002501120700002201145856012901167 2025 eng d a1861-472800aManganese-mediated cascade radical oxidative cyclization/1,6-conjugate addition of unsaturated oximes with p-quinone methides: facile access to β,β-diarylmethine substituted isoxazolines0 aManganesemediated cascade radical oxidative cyclization16conjuga cJAN0 v203 a

A simple and efficient strategy for the synthesis of structurally diverse beta,beta-diarylmethine substituted isoxazoline derivatives have been developed. This approach employs a manganese-promoted oxidative cyclization coupled with a 1,6-conjugate addition of unsaturated oximes to p-quinone methides. The key features of this study include the formation of C-O and C-C bonds through intramolecular and intermolecular interactions, facilitated by in situ generated iminoxyl radicals. beta,beta-diarylmethine substituted isoxazolines, bearing a wide range of functional groups, were isolated in high yields.

10ap-Quinone methide10adiarylmethine substituted isoxazolines10aIminoxy radical10aManganese catalyzed1 aVara, Vijay1 aThete, Kishor, R.1 aGhotekar, Ganesh, S.1 aMuthukrishnan, M. uhttps://library.ncl.res.in/content/manganese-mediated-cascade-radical-oxidative-cyclization16-conjugate-addition-unsaturated