RNAi Reveals Phase-Specific Global Regulators of Human Somatic Cell Reprogramming.

Incomplete knowledge of the mechanisms at work continues to hamper efforts to maximize reprogramming efficiency. Here, we present a systematic genome-wide RNAi screen to determine the global regulators during the early stages of human reprogramming. Our screen identifies functional repressors and effectors that act to impede or promote the reprogramming process.

Systematic identification of factors for provirus silencing in embryonic stem cells.

Embryonic stem cells (ESCs) repress the expression of exogenous proviruses and endogenous retroviruses (ERVs). Here, we systematically dissected the cellular factors involved in provirus repression in embryonic carcinomas (ECs) and ESCs by a genome-wide siRNA screen. Histone chaperones (Chaf1a/b), sumoylation factors (Sumo2/Ube2i/Sae1/Uba2/Senp6), and chromatin modifiers (Trim28/Eset/Atf7ip) are key determinants that establish provirus silencing.

Highly enantioselective addition of 1,3-diynes to aldehydes catalyzed by a zinc-amino alcohol complex.

Asymmetric catalysis: A highly enantioselective and efficient procedure for the amino alcohol-zinc-catalyzed addition of 1,3-diynes to various aromatic, α,β-unsaturated, and aliphatic aldehydes has been developed. The present catalytic system was successfully applied in the concise synthesis of natural products such as (S)-strongylodiols A and B (see scheme).

Catalytic asymmetric tandem transformations triggered by conjugate additions.

The development of efficient methods to access complex molecules with multistereogenic centers has been a substantial challenge in both academic research and industrial applications. One approach to this challenge is catalytic asymmetric tandem transformations, which allow a rapid increase in molecular complexity from readily available starting materials to produce enantiopure compounds. In recent years, considerable efforts have been directed towards the development of asymmetric tandem transformations.

Liquid-phase synthesis of chiral tartrate ligand library for enantioselective sharpless epoxidation of allylic alcohols.

This paper reports a successful development of a group of efficient soluble polymer-supported chiral tartrate ligands by liquid-phase synthesis for Sharpless epoxidation of a variety of allylic alcohols through ligand diversity. The influence of substituent in chiral tartrate ligands on the enantioselectivities of the reaction was disclosed. Moderate chemical yields and good enantiomeric excesses were obtained by using soluble polymer-supported tartrate ester in the epoxidation of allylic alcohols with Ti(O-i-Pr)(4)/tert-butyl hydroperoxide.

[Preparation of cellulose-based chiral stationary phase and enantioseparation of ethoxyfen-ethyl by high performance liquid chromatography].

Cellulose-tris (3,5-dimethylphenylcarbamate) was prepared after a reported method, and was confirmed by infrared spectroscopy and elemental analysis. Then it was coated onto an amino-propylated mesopore spherical silica gel. The final product was used as the chiral stationary phase of high performance liquid chromatography for the enantioseparation of a novel herbicide ethoxyfen-ethyl.

[Synthesis of a new cyclodextrin derivative and its application as CGC chiral stationary phase in determination of enantiomeric excess].

A new cyclodextrin (CD) derivative, 2,6-di-O-benzyl-3-O-valeryl-beta-CD, was synthesized and characterized by 1H NMR and IR. Using the beta-CD derivative as chiral stationary phase of capillary gas chromatography, one chiral column was prepared. On this column, the enantiomeric excesses (e.