In light of the growing scarcity of petroleum-based raw materials, carbon dioxide (CO2) is becoming increasing attractive as organic carbon source. In this perspective, formic acid (HCOOH) might be an interesting bio-renewable solution to store, transport, and activate carbon dioxide for the synthesis of value-added chemicals. Herein, HCOOH has been successfully used as C1 building block for the synthesis of a library of alcohols via a catalysed oxo-synthesis, under green experimental conditions

Different maleimide derivatives were synthesized and assayed for their in vitro activity on the soil inhabiting, plant-parasitic nematode Meloidogyne incognita, also known as root-knot nematode. The compounds maleimide, N-ethylmaleimide, N-isopropylmaleimide, and N-isobutylmaleimide showed the strongest nematicidal activity on the second stage juveniles of the root-knot nematode with EC50/72h values of 2.6 ± 1.3, 5.1 ± 3.4, 16.2 ± 5.4, and 19.0 ± 9.0 mg/L, respectively. We also determined the nematicidal activity of copper sulfate, finding an EC50 value of 48.6 ± 29.8 mg/L. When maleimide at 1 mg/L was tested in combination with copper sulfate at 50 mg/L, we observed 100% mortality of the nematodes. We performed a GC-MS metabolomics analysis after treating nematodes with maleimide at 8 mg/L for 24 h. This analysis revealed altered fatty acids and diglyceride metabolites such as oleic acid, palmitic acid, and 1-monopalmitin. Our results suggest that maleimide may be used as a new interesting building block for developing new nematicides in combination with copper salts.

In a new version of the Fischer indole synthesis, primary and secondary alcohols have been catalytically oxidized in the presence of phenylhydrazines and protic or Lewis acids to give the corresponding indoles. The overall reaction can be accomplished in one step, and the use of alcohols instead of aldehyes or ketones as starting materials has several advantages in terms of a large selection of reagents, easy handling, and safety of the process.

An efficient one-pot ruthenium-catalyzed hydrogen-transfer strategy for a direct access to α,β-unsaturated aldehydes has been developed. The employment of enolates prepared in situ from alcohols avoided handling unstable aldehydes and provided a very appealing route to different cinnamaldehydes substituted in position 2. A silica-grafted amine was used as phase-switch tag leading to a selective one-pot process in favor of cross-dehydrogenative coupling products.

A ruthenium‐catalysed dehydrogenative cross‐coupling of primary alcohols and imines in the presence of TFA provided a library of differently substituted quinolines. Imines can be prepared in situ from various anilines and several benzyl alcohols using a ruthenium‐catalysed hydrogen‐transfer procedure. Without changing the catalyst, quinolines can be obtained in moderate to good yields by adding various primary alcohols in the presence of TFA (30 mol%) via a “telescopic” protocol. The use of alcohols, the absence of strong oxidants and the diversity of potential starting materials make this modern version of the Skraup reaction superior to most of the conventional quinoline syntheses.magnified image

H‐substituted imines are elusive compounds formed when aldehydes or ketones are mixed with ammonia. However, this class of molecules can be prepared through selective removal of a hydrogen molecule from a primary amine using a transition metal catalyst. This biomimetic transformation, previously employed for the N‐alkylation of anilines, is applied here to a domino preparation of differently substituted indoles from aliphatic primary amines and arylhydrazines. Several different linear and branched aliphatic primary amines are oxidized with reusable palladium on charcoal to the corresponding primary imines entrapped as arylhydrazones that can be isolated as such. Arylhydrazones can be further converted into N‐alkylindole derivatives via an acid‐mediated indolisation reaction. The one‐pot domino hydrogen transfer Fischer indole synthesis under heterogeneous catalysis is also possible, giving access to diverse substituted indoles, including NH indoles obtained after deprotection of the corresponding benzyl compounds. The truly heterogeneous nature of the catalyst was demonstrated by recycling the catalyst in the same reaction, and in other palladium‐catalysed transformations.magnified image

A microwave‐promoted and Ru‐catalyzed procedure is developed to couple two different primary alcohols of type (I) and (II) to yield α,β‐unsaturated aldehydes.

A Mild and Efficient Synthesis of Substituted Quinolines via a Cross-Dehydrogenative Coupling of (Bio)available Alcohols and Aminoarenes. -(MURA, M. G.; RAJAMAEKI, S.; DE LUCA, L.; CINI, E.; PORCHEDDU*, A.; Adv. Synth. Catal. 357 (2015) 2-3, 576-582, http://dx.doi.org/10.1002/adsc.201400815 ; Dip. Chim. Farm., Univ. Sassari, I-07100 Sassari, Italy; Eng.) -G. Mueller 26-194