Author pages are created from data sourced from our academic publisher partnerships and public sources.
Tosylation and acylation of cellulose in 1-allyl-3-methylimidazolium chloride
Tosylation and acylation of cellulose were performed under mild reaction conditions using imidazolium based ionic liquids (ILs) as solvents. The non-degradative nature, lower viscosity, as well as… Expand
Photoinduced Electron Transfer in Phytochlorin-(60)Fullerene Dyads
- N. Tkachenko, Lasse Rantala, A. Tauber, J. Helaja, P. Hynninen, H. Lemmetyinen
- 25 September 1999
Novel molecular electron donor−acceptor (DA) dyads, composed of a phytochlorin donor and a fullerene acceptor, have been photochemically characterized. In these dyads, a pyrrolidine spacer group… Expand
Cycloisomerization of 2-alkynylanilines to indoles catalyzed by carbon-supported gold nanoparticles and subsequent homocoupling to 3,3'-biindoles.
- Jesus E Perea-Buceta, Tom Wirtanen, +6 authors J. Helaja
- Chemistry, Medicine
- Angewandte Chemie
- 4 November 2013
However, the reductive nature of those conditions limited thereaction scope and precluded the possibility of furthercascade functionalization. Soon after, Somorjai, Toste, andco-workers reported that… Expand
Locked conformations for proline pyrrolidine ring: synthesis and conformational analysis of cis- and trans-4-tert-butylprolines.
- A. Koskinen, J. Helaja, Esa T. T. Kumpulainen, J. Koivisto, Heidi Mansikkamäki, K. Rissanen
- Chemistry, Medicine
- The Journal of organic chemistry
- 1 July 2005
The motional restrictions of the proline pyrrolidine ring allow this secondary amine amino acid to act as a turn inducer in many peptides and proteins. The pyrrolidine ring is known to exhibit two… Expand
Isolation of a zwitterionic dienegold(III) complex intermediate in the direct conversion of enyne-amines to cyclopentadienes.
Gold-mediated homogeneous catalysis has shown, recently, its power, uniqueness, and versatility especially in electrophilic activation of alkynes for nucleophilic attack. Cycloisomerization of… Expand
1H and 13C NMR spectra of the methanolic allomerization products of 132(R)‐chlorophyll a
The spontaneous autoxidation (allomerization) of 132(R)‐chlorophyll a in methanol produces seven main products containing three epimer pairs. The 1H and 13C NMR spectra of these products in… Expand
Cationic Gold Catalysis with Pyridine-Tethered Au(III) NHC-Carbenes: An Experimental and DFT Computational Study
A novel strategy is developed to produce catalytically active cationic Au(III) species by pyridine-tethered NHC complexes. The catalytic properties of two NHC complexes, equipped with distinct… Expand
Development of Bis(2‐picolyl)amine–Zinc Chelates for Imidazole Receptors
New phenyl and phenol bis(2-picolyl)amine (Dpa) derivatives have been synthesized in order to generate zinc chelates for imidazole anion receptors. Previously, binuclear phenolic zinc and copper… Expand
NH Tautomerism in the Dimethyl Ester of Bonellin, a Natural Chlorin
Tautomeric switching and metal-cation sensing of ligand-equipped 4-hydroxy-/4-oxo-1,4-dihydroquinolines.
Novel 4-hydroxyquinoline (4HQ) based tautomeric switches are reported. 4HQs equipped with coordinative side arms (8-arylimino and 3-piperidin-1-ylmethyl groups) were synthesized to access O- or… Expand