00912nas a2200157 4500008004100000245008000041210006900121260000800190300001600198490000700214520036100221100002000582700002200602700001900624856011100643 2009 eng d00aCopper-catalyzed synthesis of 2-unsubstituted, n-substituted benzimidazoles0 aCoppercatalyzed synthesis of 2unsubstituted nsubstituted benzimi cNOV a9570ā€“95720 v743 a

An efficient copper-catalyzed intramolecular arylation of formamidines forming 2-unsubstituted benzimidazoles in excellent yields is reported. Sixteen examples bearing sterically demanding substituents on nitrogen like Mes, 2,6-diisopropylphenyl, or 2-tert-butylphenyl and tolerating various functional groups demonstrate the utility of this method.

1 aHirano, Keiichi1 aBiju, Akkattu, T.1 aGlorius, Frank uhttps://library.ncl.res.in/content/copper-catalyzed-synthesis-2-unsubstituted-n-substituted-benzimidazoles01031nas a2200169 4500008004100000245008000041210006900121260000800190300001800198490000800216520044700224100002000671700002200691700001700713700001900730856011200749 2009 eng d00aN-heterocyclic carbene-catalyzed hydroacylation of unactivated double bonds0 aNheterocyclic carbenecatalyzed hydroacylation of unactivated dou cSEP a14190ā€“141910 v1313 a

An intramolecular N-heterocyclic carbene (NHC)-catalyzed hydroacylation of unactivated double bonds is reported. Systematic variation of the catalyst structure revealed an N-mesitylthiazolylidene annulated with a seven-membered ring to be especially reactive. This NHC enables a unique Cāˆ’C bond-forming reaction to afford substituted chroman-4-ones in moderate to excellent yields, even ones containing all-carbon quaternary centers.

1 aHirano, Keiichi1 aBiju, Akkattu, T.1 aPiel, Isabel1 aGlorius, Frank uhttps://library.ncl.res.in/content/n-heterocyclic-carbene-catalyzed-hydroacylation-unactivated-double-bonds01031nas a2200181 4500008004100000245010600041210006900147260000800216300001600224490000600240520031700246653007500563100002200638700002000660700002100680700001900701856012900720 2009 eng d00aSwitching the electron-donor properties of n-heterocyclic carbenes by a facile deprotonation strategy0 aSwitching the electrondonor properties of nheterocyclic carbenes cDEC a1786ā€“17890 v93 a

Flip the switch! The facile and distinct variation of the electronic properties of an N-heterocyclic carbene (NHC) ligand is reported. In this process, a simple deprotonation/protonation strategy can render the NHC to be an electron-poor or an electron-rich NHC ligand: one ligand, two electronic natures.

10acarbenes; electronic properties; enolates; heterocycles; ligand design1 aBiju, Akkattu, T.1 aHirano, Keiichi1 aFrohlich, Roland1 aGlorius, Frank uhttps://library.ncl.res.in/content/switching-electron-donor-properties-n-heterocyclic-carbenes-facile-deprotonation-strategy