N-Heterocyclic carbenes promote the formal [2+2] cycloaddition of ketenes with N-tosyl imines to give the corresponding beta-lactams in good to excellent isolated yields; chiral NHCs give beta-lactams in high e.e. after crystallisation.

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A flexible, modular ynamide synthesis is reported that uses trichloroethene as an inexpensive two carbon synthon. A wide range of amides and electrophiles can be converted to the corresponding ynamides, importantly including acyclic carbamates, hindered amides, and aryl amides. This method thus overcomes many of the limitations of other approaches to this useful functionality.

The catalytic activity and enantioselectivity in the kinetic resolution of (±)-1-naphthylethanol with a range of structurally related 3,4-dihydropyrimido[2,1-b]benzothiazole-based catalysts is examined. Of the isothiourea catalysts screened, (2S,3R)-2-phenyl-3-isopropyl substitution proved optimal, giving good levels of selectivity in the kinetic resolution of a number of secondary alcohols (S values up to >100 at ~50% conversion). Low catalyst loadings (0.10-0.25 mol%) of the optimal isothiourea can be used to generate enantiopure alcohols (>99% ee) in good yields.

The cycloisomerization of enynes catalyzed by Pd(OAc) and bis-benzylidene ethylenediamine (bbeda) is a landmark methodology in transition-metal-catalyzed cycloisomerization. However, the mechanistic pathway by which this reaction proceeds has remained unclear for several decades. Here we describe mechanistic investigations into this reaction using enynamides, which deliver azacycles with high regio- and stereocontrol. Extensive H NMR spectroscopic studies and isotope effects support a palladium(II) hydride-mediated pathway and reveal crucial roles of bbeda, water, and the precise nature of the Pd(OAc) pre-catalyst. Computational studies support these mechanistic findings and lead to a clear picture of the origins of the high stereocontrol that can be achieved in this transformation, as well as suggesting a novel mechanism by which hydrometalation proceeds.

Benzyne, generated by the oxidation of 1 -aminobenzotriazole with lead tetra-acetate, adds to 1.3-dienes and reacts with nucleophiles in moderate to excellent yields, However, it generally dimerises much faster than it adds to heterocyclic dienes. Addition of benzyne to 2-methyl-and 2-benzyl-benzotriazole gives 1 -phenylbenzotriazole. Mechanisms for these reactions are proposed. Benzyne, generated oxidatively, does not add appreciably to mono-olefins.

Since the sudden emergence of COVID-19 global pandemic, all educational institutions have looked to move resources and delivery online. Some institutions had already embraced delivering instruction in this way, however, broader adaptation to this teaching style is new to many educators.While the teaching of theoretical concepts is more easily transferred to a blended learning environment, the teaching of practical chemistry poses significant challenges, yet it is crucial to the chemist's identity.Here we describe the establishment of a new, international, network to consider how practical chemistry can be taught outside of the traditional laboratory environment and invite readers of this special edition of the journal to join. Meeting fortnightly and maintaining links through a shared networked drive between meetings, the network has been accessed by over 100 delegates in the UK, mainland Europe, North America and Australasia. The traditional siloes of chemistry have not defined the discussions, which have instead focused on logistical aspects such as social distancing and the pastoral role of the laboratory environment. Initial evaluation shows the network is valued by its members and is making progress towards its aims.

Screening of a range of azolium salts, bases and solvents for reactivity indicates that triazolinylidenes, generated in situ with KHMDS in THF, promote the Steglich rearrangement of oxazolyl carbonates with high catalytic efficiency (typical reaction time 5 min at <1.5 mol % NHC). This protocol shows wide substrate applicability, even allowing the efficient generation of vicinal quaternary centers. An improved experimental procedure is also described that allows a simplified one-pot reaction protocol to be employed with similarly high catalytic efficiency.