DNA methylation is involved in tissue-specific and developmentally regulated gene expression. Here, we screened a novel methylation gene Sox30, whose methylation might contribute to its regulation and testis development in mice. Sox30 is a member of Sox transcription factors, and is considered to be involved in spermatogonial differentiation and spermatogenesis. However, the precise function and regulatory expression pattern remain unclear. In the present study, we found that Sox30 is highly expressed in adult testes but not in ovaries. Sox30 expression begins in early development, and in the testes, it is specifically increased coincidentally with development until adulthood. Moreover, Sox30 is expressed not only in testis germ cells, but also in sertoli cells. Sox30 is hypo-methylated in testis, epididymis and lung of adult mice, in which Sox30 is expressed. By contrast, Sox30 is hypermethylated in ovary, heart, brain, liver, kidney, spleen, pancreas, muscle, intestine, pituitary gland, blood and hippocampus of adult mice, in which the Sox30 is absent. Importantly, decreased methylation at CpG islands of Sox30 is observed in mouse developmental testes after birth, which is associated with enhanced Sox30 expression. However, the hypermethylated status of Sox30 is maintained in ovaries that does not express Sox30 during this period. Further, following demethylation treatment using 5-aza-dC, Sox30 expression is restored in GC2, TM3 and TM4 cell lines. This observation convincingly confirms that methylation really contributes to Sox30 silencing. In summary, we show that Sox30 expression is under the control of DNA methylation status, and this expression pattern is associated with testis development in mice.

Density functional theory calculations are carried out to better understand the first gold-catalyzed 1,2-diarylation reactions of alkenes reported in the recent literature. The calculations on two representative reactions, aryl alkene/aryl iodide coupling pair (the aryl–I bond is located outside the aryl alkene) versus iodoaryl alkene/indole coupling pair (the aryl–I bond is located in the aryl alkene), confirm that the reaction involves a π-activation mechanism rather than the general migratory insertion mechanism in previously known metal catalysis by Pd, Ni, and Cu complexes. Theoretical results rationalize the regioselectivity of the reactions controlled by the aryl–I bond position (intermolecular or intramolecular) and also the ligand and substituent effects on the reactivity.

By performing density functional theory (DFT) calculation, this work aims at understanding the nonconventional meta-C–H arylation reaction of electronic-rich arenes with aryl iodide via a Pd/quinoxaline-based ligand/norbornene cooperative catalysis. The reaction is indicated to be initiated either from the ortho-C–H carbopalladation to give the meta-monoarylation product via a sequence of subsequent steps, including norbornene insertion, meta-C–H activation, oxidative addition, and reductive elimination via the Pd­(II)/Pd­(IV)/Pd­(II) redox cycle, norbornene extrusion, and protodepalladation, or from the para-C–H carbopalladation to form the meta-diarylation product via two sequential arylation processes following similar mechanisms. The initial carbopalladation process promoted by the ligand is characterized as the rate-determining step of the reaction. The calculated mechanism shows the distinct role of the norbornene as a transient mediator that enables the final C–H arylation at the same meta-position wherever the initial carbopalladation occurs at either ortho- or para-position. The Pd/ligand/norbornene cooperative catalysis is essential for achieving the exclusive meta-selectivity of the C–H arylation of electron-rich arenes.

This work presentsaDFT-based computational study on the regio-ande nantioselective CÀHf unctionalization of pyridines with alkenes at the relatively unreactiveC 4position, whichw as successfully achieved by Shi et al. [J. Am. Chem. Soc. 2019, 141,5 628-5634] using Ni 0 /N-heterocyclic carbene( NHC) catalysis undert he assistanceo fa na luminum-based Lewis acid additive (2,6-tBu 2 -4-Me-C 6 H 2 O) 2 AlMe (MAD).T he calculationsi ndicate that the selectivef unctionalizationi nvolves at hree-step mechanism in whichaunique H-migration assisted oxidation metalation( HMAOM) step is identified as the rate-and enantioselectivity-determining step. The newly proposed mechanism can well rationalize the experimental observation that the preferred product is the endo-type (vs. exo-type), R-configuration (vs. S-configuration) product at the C4 (vs. C2) position, and also unveil the reasons that the NHC ligand and the MAD additive can facilitate the reaction.[a] X.Scheme1.Arepresentative example of MAD-induced Ni 0 /NHC-catalyzed regio-and enantioselective CÀHc yclization of alkene-tethered pyridine 1 reported by Shi and co-workers. [29] Scheme2.Proposed reaction pathway by Shi et al. [29] for the Ni 0 -catalyzed regio-a nd enantioselectiveC ÀHa ctivationa tt he C4-positiono falkene-tethered pyridine (1). Figure 7. (a) Geometries and the relativee nergies (in kcal mol À1 )o fkey intermediates and rate-determining transitions tates for the endo-type cyclization at the C4-position in the Ni 0 -catalyzed reaction with and without presence of the NHC ligand, and (b) HOMOs andLUMOso fNi(cod),p yridine-MAD adduct 3, and Ni(NHC).