Using a halogen bond (XB) donor and Schreiner's thiourea as cooperative catalysts, various amides, including the asparagine residues of several peptides, were directly coupled with glycosyl trichloroacetimidates to give unique N-acylorthoamides in good yields. Synthetic applications of N-acylorthoamides, including rearrangement to the corresponding β-N-glycoside, were also demonstrated.

A fair exchange: in the title reaction, alkynyllithium serves as an initiator for benzyne generation through an iodine-lithium exchange. When performed in the presence of stoichiometric amounts of a nucleophile, the generated benzyne undergoes attack by lithio nucleophiles to generate aryllithium, which is then iodinated by iodoalkyne to give the iodoarenes 1.

The direct 2‐deoxyglycosylation of nucleophiles with glycals leads to biologically and pharmacologically important 2‐deoxysugar compounds. Although the direct addition of hydroxyl and sulfonamide groups have been well developed, the direct 2‐deoxyglycosylation of amide groups has not been reported to date. Herein, we show the first direct 2‐deoxyglycosylation of amide groups using a newly designed Brønsted acid catalyst under mild conditions. Through mechanistic investigations, we discovered that the amide group can inhibit acid catalysts, and the inhibition has made the 2‐deoxyglycosylation reaction difficult. Diffusion‐ordered two‐dimensional NMR spectroscopy analysis implied that the 2‐chloroazolium salt catalyst was less likely to form aggregates with amides in comparison to other acid catalysts. The chlorine atom and the extended π‐scaffold of the catalyst played a crucial role for this phenomenon. This relative insusceptibility to inhibition by amides is more responsible for the catalytic activity than the strength of the acidity.

Using ah alogen bond (XB) donor and Schreiners thiourea as cooperative catalysts,various amides,including the asparagine residues of several peptides,w ere directly coupled with glycosyl trichloroacetimidates to give unique N-acylorthoamides in good yields.S ynthetic applications of N-acylorthoamides,including rearrangement to the corresponding b-Nglycoside,were also demonstrated.

Organo‐radical catalysts have recently attracted great interest, and the development of this field can be expected to broaden the applications of organocatalysis. Herein, the first example of a radical‐generating system is reported that does not require any photoirradiation, radical initiators, or preactivated substrates. The oxidative C−C‐bond cleavage of 2‐substituted cyclohexanones was achieved using an azolium salt and a hydroquinone as co‐catalysts. A catalytic mechanism was proposed based on the results of diffusion‐ordered spectroscopy and cyclic voltammetry measurements, as well as computational studies.