Hydrogen Transfer-Mediated Multicomponent Reaction for Direct Synthesis of Quinazolines by a Naphthyridine-Based Iridium Catalyst.

Selective linkage of renewable alcohols and ammonia into functional products would not only eliminate the prepreparation steps to generate active amino agents but also help in the conservation of our finite fossil carbon resources and contribute to the reduction of CO2 emission. Herein the development of a novel 2-(4-methoxyphenyl)-1,8-naphthyridine-based iridium (III) complex is reported, which exhibits excellent catalytic performance toward a new hydrogen transfer-mediated annulation reaction of 2-nitrobenzylic alcohols with alcohols and ammonia. The catalytic transformation proceeds with the striking features of good substrate and functional group compatibility, high step and atom efficiency, no need for additional reductants, and liberation of H2O as the sole by-product, which endows a new platform for direct access to valuable quinazolines. Mechanistic investigations suggest that the non-coordinated N-atom in the ligand serves as a side arm to significantly promote the condensation process by hydrogen bonding.

[Interactive effect of N and Ca on N uptake by tomato].

To study the effect of fertilizer N and Ca on tomato plant, a pot experiment was conducted with meadow soil in Shenyang. The results showed that under the experimental condition, the N contents in stems, leaves and fruits decreased gradually along with the growth stages. For all treatments, the NO3(-)-N content in fruits, which was within the raw eatable standard, had a positive correlation to N fertilization level. Adequate application of Ca was useful to control the NO3(-)-N content. The response of N contents in stems, leaves and fruits to fertilizer N and Ca was in line with the law of diminishing marginal returns. From flowering stage to fruit expanding stage, the response of fertilizer N was most activated. The nitrate reductase activity in leaves might be greatly affected by fertilizer N, while adequate Ca fertilization could decrease it. A combined application of N and Ca could promote the nitrate reductase activity. Both soil NO3(-)-N content and electric conductivity (EC) were increased with the increasing amount of applied fertilizer N.