Discovery of Plant Growth Stimulants by C–H Arylation of 2-Azahypoxanthine

Abstract

A series of new AHX derivatives were synthesized by Pd-catalyzed C-H arylation. Their rice-growth-promoting activity was evaluated in vivo. Among the synthesized compounds, C8 phenyl-substituted AHX showed remarkable growth-promoting activity on rice. The present study shows the power and significant opportunity of C-H functionalization chemistry to rapidly transform biologically active natural products into more active compounds.

A Fairy Chemical, Imidazole-4-carboxamide, is Produced on a Novel Purine Metabolic Pathway in Rice

“…Although the molecular mechanisms, endogeny, and biosynthetic pathways of 1 and 3 in plants have already been proven, those of 2 had not been cleared. It has been reported that 1 and 3 , and 2 exhibited growth-promoting activity and growth-inhibiting activity against rice, respectively 8–10,19 . Here, the gene expression profile of rice treated with 2 showed largely reverse patterns in comparison to those of 1 and 3 , suggesting that the plant growth may be regulated by the endogenous levels of FCs.…”

“…It has been reported that 1 and 3 promoted the growth of shoots and roots of rice seedlings and 2 inhibited it 8–10,19 . However, the treatment with not only 1 or 3 but also 2 increased yields of rice and wheat grains 8,12 .…”

“…It has been reported that root-specific metal transporter and RCc3 play important roles in the regulation of metal homeostasis in Arabidopsis thaliana and elongation of root in rice, respectively 22,23 . Hence, the plant growth inhibition by 2 -treatment may be due to the down-regulation of these genes 8,19 . However, the genes of glutathione S -transferases ( GST ) were induced by treatment with 2 similar to 1 or 3 (Table 1) 9,10 .…”

Recent Advances in C–H Activation for the Synthesis of π-Extended Materials

“…Synthetic methods achieving direct site-selective arylation of other azole systems have also been described in recent years. − You reported the C–H arylation of [1,2,4]­triazolo­[1,5- a ]­pyrimidines (TAPs) at both the C3 and C7 ring positions, enabling the programmable synthesis ,− of a library of donor–acceptor molecules with mechanochromic properties (see Scheme b). The parent heterocycle 7 was first arylated at the C3 position with iodoarene substrates under copper catalysis.…”

Rapid Access to Kinase Inhibitor Pharmacophores by Regioselective C–H Arylation of Thieno[2,3-d]pyrimidine

“…The synthetic utility was highlighted by the regiodivergent access to aryl thieno­[2,3- d ]­pyrimidines 3p (NHTP25) and 2w , which show CK2 inhibitory potency. The installation of aryl groups into the original pharmacophore scaffolds has a potential to dramatically alter their biological activities . For this reason, the rapid synthesis of aryl thieno­[2,3- d ]­pyrimidine derivatives with our C–H arylations will be beneficial not only for the target-oriented synthesis but also for the divergent-oriented synthesis to construct a series of novel bioactive candidates.…”