RESUMO
Gold (III) cyclometalated based amphiphiles in aqueous media have been revealed with excellent supramolecular transformations to external stimuli to open new pathways for soft functional material fabrications. Herein, we report a new chiral cyclometalated gold (III) amphiphile (GA) assembling into lamellar nanostructures in aqueous media confirmed with transmission electron microscopy (TEM). Counterion exchange with D-, L-, or racemic-camphorsulfonates features the significant supramolecular helicity enhancements, enabling transformations of GA from lamellar structure to vesicles and to nanotubes with multi-equivalents of counterion. The limited cytotoxicity of GA in aqueous media exhibits good biocompatibility.
RESUMO
Invited for this month's cover are the collaborating groups of Prof. Man-Kin Wong and Dr. Franco King-Chi Leung from The Hong Kong Polytechnic University. The cover picture illustrates chiral gold (III) amphiphiles assemble into tubular supramolecular structures in aqueous media through counterion controlled pathway. The nanostructures were further demonstrated with good cytocompatibility in aqueous media. More information can be found in the Research Article by Man-Kin Wong, Francoâ King-Chi Leung, and co-workers.
RESUMO
An efficient chiral phosphine-catalyzed asymmetric substitution reaction of MBH carbonates with 3-substituted benzofuran-2(3H)-ones or 3-substituted oxindoles has been described in this context, giving the corresponding allylic alkylation products bearing adjacent quaternary and tertiary stereogenic centers in high yields, moderate diastereoselectivities and high enantioselectivities under mild conditions.
Assuntos
Compostos Alílicos/química , Benzofuranos/química , Carbonatos/química , Indóis/química , Fosfinas/química , Alquilação , Catálise , Oxindóis , EstereoisomerismoRESUMO
Chiral phosphine-Schiff base type ligand L8 prepared from (R)-(-)-2-(diphenylphosphino)-1,1'-binaphthyl-2'-amine was found to be a fairly effective ligand for Cu(I)-promoted enantioselective chlorination of ß-keto esters to give the corresponding products in high yields and with moderate enantioselectivities.
RESUMO
Asymmetric gold catalysis has been rapidly developed in the past ten years. Breakthroughs have been made by rational design and meticulous selection of chiral ligands. This review summarizes newly developed gold-catalyzed enantioselective organic transformations and recent progress in ligand design (since 2016), organized according to different types of chiral ligands, including bisphosphine ligands, monophosphine ligands, phosphite-derived ligands, and N-heterocyclic carbene ligands for asymmetric gold(I) catalysis as well as heterocyclic carbene ligands and oxazoline ligands for asymmetric gold(III) catalysis.
RESUMO
Epidemiological studies have demonstrated that the genetic factors partly influence the development of same-sex sexual behavior, but most genetic studies have focused on people of primarily European ancestry, potentially missing important biological insights. Here, we performed a two-stage genome-wide association study (GWAS) with a total sample of 1478 homosexual males and 3313 heterosexual males in Han Chinese populations and identified two genetic loci (rs17320865, Xq27.3, FMR1NB, Pmeta = 8.36 × 10-8, OR = 1.29; rs7259428, 19q12, ZNF536, Pmeta = 7.58 × 10-8, OR = 0.75) showing consistent association with male sexual orientation. A fixed-effect meta-analysis including individuals of Han Chinese (n = 4791) and European ancestries (n = 408,995) revealed 3 genome-wide significant loci of same-sex sexual behavior (rs9677294, 2p22.1, SLC8A1, Pmeta = 1.95 × 10-8; rs2414487, 15q21.3, LOC145783, Pmeta = 4.53 × 10-9; rs2106525, 7q31.1, MDFIC, Pmeta = 6.24 × 10-9). These findings may provide new insights into the genetic basis of male sexual orientation from a wider population scope. Furthermore, we defined the average ZNF536-immunoreactivity (ZNF536-ir) concentration in the suprachiasmatic nucleus (SCN) as lower in homosexual individuals than in heterosexual individuals (0.011 ± 0.001 vs 0.021 ± 0.004, P = 0.013) in a postmortem study. In addition, compared with heterosexuals, the percentage of ZNF536 stained area in the SCN was also smaller in the homosexuals (0.075 ± 0.040 vs 0.137 ± 0.103, P = 0.043). More homosexual preference was observed in FMR1NB-knockout mice and we also found significant differences in the expression of serotonin, dopamine, and inflammation pathways that were reported to be related to sexual orientation when comparing CRISPR-mediated FMR1NB knockout mice to matched wild-type target C57 male mice.
RESUMO
Asymmetric catalysis by using novel chiral O,O'-chelated 4,4'-biphenol cyclometalated oxazoline gold(III) complexes has been developed. A high yield (≤89%) and a high enantioselectivity (≤90% ee) were achieved in asymmetric carboalkoxylation of alkynes. Enantioselectivity could be significantly improved from 19% to 90% ee by increasing the steric size of the substituent on the chiral oxazoline ligand. Catalytically active AuIII species and the origin of chiral induction are proposed.
RESUMO
[reaction: see text] Axially chiral N-heterocyclic carbene (NHC) Pd(II) complexes were prepared from optically active 1,1'-binaphthalenyl-2,2'-diamine (BINAM) and H8-BINAM and applied in the oxidative kinetic resolution of secondary alcohols using molecular oxygen as a terminal oxidant. The corresponding sec-alcohols can be obtained in good yields with moderate to good enantioselectivities.
RESUMO
Significant progress in the development of the Morita-Baylis-Hillman (MBH) reaction has been made in the past decade. Many new variations of the MBH reaction have been well exploited, affording unexpected products and novel cyclized adducts in some cases, known as "abnormal MBH reactions". The formation of abnormal MBH adducts depends on the nature of the substrates and the employed catalytic system. This article will summarize recent advances in and mechanistic insights into such "abnormal" MBH reactions, including double-MBH reactions, sila-MBH reactions, abnormal aza-MBH reactions and tandem MBH pathways.