A novel study of external Brønsted acid-assisted thiourea catalysts in the asymmetric FriedelCrafts alkylation of indoles with nitroalkenes is reported. The final 3-substituted indoles derivatives are synthesized with better results by cooperative effect between chiral thiourea and a Brønsted acid additive (1a·HA), than those obtained with sole thiourea catalyst 1a. The effect of diverse catal...

A Morita-Baylis-Hillman (MBH) reaction catalyzed by thiourea was monitored by ESI-MS(/MS) and key intermediates were intercepted and characterized. These intermediates suggest that thiourea acts as an organocatalyst in all steps of the MBH reaction cycle, including the rate-limiting proton-transfer step. DFT calculations, performed for a model MBH reaction between formaldehyde and acrolein with...

This study examines the mechanisms by which thioumeamay protect cells against toxic actions produced by platinum com plexes or nitrogen mustards. Mouse leukemia Li 210 cells were assayed for survival by colony formation in soft agamand for DNA interstrand cross-linking using the alkaline elution method. The survival of Li 2i 0 cells treated with cis-and trans Pt(Il)diamminedichloride was enhanc...

The possible presence of a urea transporter in the kidney of the gulf toadfish (Opsanus beta) and further characterization of the pulsatile facilitated transporter previously identified in its gills were investigated by comparing the extra-renal and renal handling of two urea analogues with the handling of urea. Toadfish were fitted with caudal artery and indwelling urinary ureteral catheters a...

A series of thiourea-amine bifunctional catalysts have been developed by a rational combination of prolines with cinchona alkaloids, which are connected by a thiourea motif. The catalyst 3a, prepared from L-proline and cinchonidine, was found to be a highly efficient catalyst for the conjugate addition of ketones/aldehydes to a wide range of nitroalkenes (up to 98/2 dr and 96% ee). The privileg...

Tyrosinase catalyzes two distinct sequential reactions in melanin biosynthesis: The hydroxylation of tyrosine to dihydroxyphenylalanine (DOPA) and the oxidation of DOPA to dopaquinone. Developing functional modulators of tyrosinase is important for therapeutic and cosmetic purposes. Given the abundance of thiourea moiety in known tyrosinase inhibitors, we studied other thiourea-containing drugs...

Soil fumigants are becoming an important source of volatile organic compounds (VOCs) in air, especially in some agricultural areas. In this study, we used thiourea to construct a reactive surface barrier (RSB) at the soil surface for reducing 1,3-dichloropropene (1,3-D) volatilization. The agrochemical thiourea could rapidly transform volatile 1,3-D to nonvolatile products via an SN2 nucleophil...

Au-Ag noble metal wastes represent a wide range of waste types and forms with various ballast elements and components. The thiourea process of gold and silver extraction from ores, concentrates or secondary raw materials consists of gold and silver leaching into the thiourea solution and the consequent precipitation of these metals from the solution. Due to the non-toxic character of thiourea i...

in this study, the effect of application time (immediately and one week after harvest) of some chemicals (rindite, carbon disulphide, gibberellic acid and thiourea) on breaking of dormancy and sprouting of potato (solanum tuberosum l., cv., marfona) minitubers was investigated. for the carbon disulphide (25 ml m-3 for four days) and rindite (0.2 ml l-1 for two days) application, minitubers were...