Pradeep Panyam

• PhD
• PostDoc Position at University of Stuttgart

Non‐porous polyurethane‐based monoliths were prepared under solvent‐induced phase separation conditions. They possess low specific surface areas of 0.15 m2/g, pore volumes of 1 μL/g and a non‐permanent, solvent‐induced microporosity with pore dimensions ≤ 1 nm. Mesoporosity can be introduced by varying the monomers and solvents. A tuning of the ave...

Ketones are the key functional group that recurs in chemistry and biology, and accessing them through simple and economic ways is highly desirable. Herein, we report the synthesis of unsymmetrical ketones from abundant toluene and alkyl esters, where volatile alcohols are the sole byproduct. This protocol applies to a repertoire of substrates beari...

Polymeric mesoporous monoliths were prepared via ring-opening metathesis polymerization (ROMP) from norbornene (NBE), 1,4,4a,5,8,8a-hexahydro-1,4,5,8-exo,endo-dimethanonaphthalene (DMN-H6), tris(norborn-2-enylmethylenoxy)methylsilane and the 1st-generation Grubbs catalyst [RuCl2(PCy3)2(CHC6H5)] in the presence of 2-propanol and toluene and...

Rh(I) NHC and Rh(III) Cp* NHC complexes (Cp*=pentamethylcyclopentadienyl, NHC=N‐heterocyclic carbene=pyrid‐2‐ylimidazol‐2‐ylidene (Py−Im), thiophen‐2‐ylimidazol‐2‐ylidene) are presented. Selected catalysts were selectively immobilized inside the mesopores of SBA‐15 with average pore diameters of 5.0 and 6.2 nm. Together with their homogenous progen...

The chemistry of both low- and high-oxidation state vanadium, niobium, tantalum, chromium, molybdenum and tungsten N-heterocyclic carbene (NHC) and mesoionic carbene complexes is outlined. This article mostly focuses on their synthesis, relevant structural aspects and peculiarities, but also addresses some applications and use of these complexes, e...

Reaction of CrCl2(N‐tBu)2 with 1,3‐dimethylimidazol‐2‐ylidene (IMe), 1,3‐dimethyl‐4,5‐dichloroimidazol‐2‐ylidene (IMeCl2), 1,3‐di(2‐propyl)imidazol‐2‐ylidene (IPr), 1,3‐dimesitylimidazol‐2‐ylidene (IMes) and 1,3‐bis(2,6‐(2‐Pr)2C6H3)imidazol‐2‐ylidene (IDipp) yields the corresponding N‐heterocyclic carbene (NHC) adducts CrCl2(IMe)(N‐tBu)2 (1), CrCl2...

Predominantly, aggressive acid chlorides and stoichiometric coupling reagents are employed in the acylating process for synthesizing carbonyl tethered heterocycles. Herein, we report simple acyl sources, viz. methyl and phenyl esters which acylate oxindoles via mixed Claisen condensation. This straightforward protocol is mediated by LiHMDS and KOtB...

Rationally designed fluorene-based mono- and bimetallic Pd-PEPPSI complexes were synthesized and demonstrated to be effective for the one-pot sequential α-arylation/alkylation of oxindoles. This streamlined approach offers efficient access to functionalized 3,3-disubstituted oxindoles in excellent yields (up to 89%) under mild reaction conditions.

Topologically constrained naphthalimide appended Pd-NHCs were synthesized and characterized. These structurally related complexes were catalytically compared with the previously synthesized Pd-NHC in the regioselective heteroannulation of o-haloanilines and arylethynyl-trimethylsilane. The unique effect of the additive on the product selectivity ha...

Monometallic and bimetallic palladium(II)/N‐heterocyclic carbene complexes appended with naphthalimide or bisnaphthalimide moieties were designed, synthesized, and characterized. Employment of these catalysts brings about the step‐economic and regioselective heteroannulation of tertiary propargyl alcohols with o ‐haloanilines resulting in biologica...

Palladium-catalyzed synthetic methodology has been developed for the synthesis of 2-aminobenzenesulfonic acids from benzothiazoles in good to excellent yields using chloramine-B in alkaline (pH 12) acetonitrile/water (1:1) at 80 °C.