SUMMARY Natural killer T (NKT) cells recognize glycolipids presented by CD1d. The first antigen described, α-galactosyl ceramide (αGalCer), is a potential anti-cancer agent whose activity depends upon IFN-γ secretion. Here we report two analogs of αGalCer based on a naturally occurring glycosphingolipid, plakoside A. These compounds induce enhanced IFN-γ that correlates with detergent resistant binding to CD1d and an increased stability of the lipid-CD1d complexes on antigen presenting cells. Structural analysis on one of the analogs indicates that it is bound more deeply inside the CD1d groove, suggesting tighter lipid-CD1d interactions. This is the first example where structural information provides an explanation for the increased lipid-CD1d stability, likely responsible for the Th1 bias. We provide insights into the mechanism of IFN-γ inducing compounds, and since our compounds activate human NKT cells, they could have therapeutic utility.

This review delves into the synthesis of cationic-functionalized oligothiophenes and polythiophenes, their properties, and their diverse applications from the year 2002 to 2019. Pristine polythiophene chains are hydrophobic and are not easily converted into a form that is useful for broad applications or for device fabrications. Functional modification of the polymer side chain especially with cationic pendant groups imparts favorable properties to the system, such as solubility in aqueous medium and affinity with anions and negatively charged species, alongside the extensive π conjugation that provides unique optoelectronic characteristics. This review provides a detailed account of the design and the different synthetic strategies to access cationic polythiophenes (CPTs) via chemical oxidation using iron(III) chloride (FeCl 3 ), via metal catalyzed and initiated polymerization, and via postpolymerization functionalization approaches. CPTs have been traditionally used in sensing and as a component in optoelectronic devices; the utility of these systems has been extended to biomedical applications, such as nonviral gene delivery, cell targeting and imaging, anticancer, antifungal, and bactericidal actions, and biofilm formation, and to use as a molecular probe. A summary and outlook are also presented, discussing the remaining challenges and the future direction for this field.

[structure: see text] The new BIPI ligands are phosphinoimidazolines that can be electronically tuned in three different ligand regions to explore electronic effects in asymmetric catalysis. Their application to the asymmetric Heck reaction (AHR) in the creation of a chiral quaternary center is described. Enantioselectivity is shown for the first time to depend linearly on phosphine electron density. Changing the ligand basicity by variation of the R(2) or R(3) substituents reverses facial selectivity.

A new water soluble cationic polythiophene derivative, poly(N,N,Ntrimethyl-3-(2-(thiophen-3-yl)acetamido)propan-1-aminium iodide), was synthesized via two consecutive post-polymerization functionalizations of poly(methyl 2-(thiophen-3-yl)acetate). This conjugated polymer binds DNA at N/P ¼ 5 and forms polyplexes at N/P ¼ 10. Its potential use as a theranostic gene delivery vehicle is investigated here.

Sphinganines can be synthesized in just three steps from easily prepared serine-derived Weinreb amide 4. Pre-deprotonation of the acidic (N-H and O-H) protons of 4 allows for its efficient conversion to amino ketones 5. Such ketones can be selectively reduced to either erythro- or threo-sphinganines. Partially protected sphinganines 11 are also readily accessible in five steps from 4. Thus, Weinreb amide 4 represents one of the most versatile templates described to date for sphinganine synthesis.