Cesium-Fluoride-Promoted Synthesis of Stable Organocesium Reagents and Their Ambident Reactivities with Arynes.

Described are the diverse reactivities of novel, stable, ambident thio-organocesium reagents (bearing electron withdrawing groups) against benzynes. Reactions at reflux temperature predominantly led to the generation of various functionalized stable sulfonium ylides and at 40 °C the same reaction underwent direct c-arylation. Furthermore, lack of internal hydrogen on the cesium reagent helped to produce different ortho-bifunctional arynes in both the reactions. Interestingly, depending on the reactivities of substrates, the one-pot tri-component procedure generated either ylides or σ-bond insertion products.

Iodine and ammonium persulfate mediated activation of DMSO: an approach to N-formylation of amides and synthesis of isatins.

An efficient strategy towards N-formylation of amides and oxidation of indolines to isatins is described. This method employs readily available (NH4)2S2O8, I2, and DMSO. The given method features operational simplicity, excellent functional group tolerance, broad substrate scope, and fast kinetics. Moreover, the method was applied to the synthesis of the natural product alatamide. Notably, DMSO plays three vital roles: a formyl group source, an oxidant, and a solvent.

Sulfonyl-Promoted Michaelis-Arbuzov-Type Reaction: An Approach to S/Se-P Bonds.

By facilitating the chemical conversion of thiols to thiosulfonates, phosphoramidite/phosphite bearing sp3-hybridized carbon serves as an ideal coupling material to forge new connections at room temperature. In this work, a functional group-induced, additive-free, novel, S-P bond-forming approach is presented. This protocol exhibits good functional group tolerance with wide applications that include phosphorylation of cysteine derivatives, development of a one-pot approach to mixed unsymmetrical thiophosphonates, and extension of the concept to different Se-P bonds. Meticulously, our reaction also generated a S-P bond against cyclic 1,2-dithiane-1-dioxide in a byproduct-free manner. These Michaelis-Arbuzov-type reactions are easy to conduct, work efficiently in a reduced reaction time, and are applicable to gram-scale preparation as well.

Introducing Oxo-Phenylacetyl (OPAc) as a Protecting Group for Carbohydrates.

A series of oxo-phenylacetyl (OPAc)-protected saccharides, with divergent base sensitivity profiles against benzoyl (Bz) and acetyl (Ac) were synthesized, and KHSO5/AcCl in methanol was identified as an easy, mild, selective, and efficient deprotecting reagent for their removal in the perspective of carbohydrate synthesis. Timely monitoring of AcCl reagent was supportive in both sequential and simultaneous deprotecting of OPAc, Bz, and Ac. The salient feature of our method is the orthogonal stability against different groups, its ease to generate different valuable acceptors using designed monosaccharides, and use of OPAc as a glycosyl donar.

Iodine-DMSO-promoted divergent reactivities of arylacetylenes.

An unprecedented set of efficient, economical, atom-economic and exceedingly selective I2-DMSO-promoted methods is described for the generation of different structures. The reaction represents the first of its kind, involving the use of different iodine concentrations, temperatures, acids and salt to adjust the selectivity for the synthesis of different alkenes, α-functionalized ketones and α-ketomethylthioesters.