Combination of Enabling Technologies to Improve and Describe the Stereoselectivity of Wolff–Staudinger Cascade Reaction

Abstract

A new single-mode bench-top resonator was evaluated for the microwave-assisted flow generation of primary ketenes by thermal decomposition of -diazoketones at high temperature. A number of amides and -lactams were obtained by in situ ketene generation and reaction with amines and imines respectively in good to excellent yields. The preferential formation of trans-configured -lactams was observed during the [2+2] Staudinger cycloaddition of a range of ketenes with different imines under controlled reaction conditions. Some insights into the mechanism of this reaction at high temperature are reported and a new web-based molecular viewer, which takes advantage from augmented reality (AR) technology, is also described for a faster interpretation of computed data.

Access to 2-Oxoazetidine-3-carboxylic Acids Derivatives via Thermal Microwave-Assisted Wolff Rearrangement of 3-Diazotetramic Acids in the Presence of Nucleophiles

“…According to literature data, the vicinal coupling constants in the 6 3,4-disubsituted β-lactam cycle have characteristic values for the two diastereomers, lying in the intervals 5.5-6.0 Hz and 1.5-2.5 Hz for the cis and trans forms, respectively. [32,33] This makes it easy to assign the stereochemistry of the products obtained. Additional confirmation was gained from X-ray analysis data for structure 3r (Scheme 2).…”

A New World for Chemical Synthesis?

“…This 'mixed reality' approach will have increasing importance in workplace safety, especially in laboratory environments and larger-scale operations in process development and manufacturing. [23] Access to live equipment parameters, material composition streams and atmospheric parameters such as gas compositions will give workers increased insight into their operations. Wearable sensors, [24] potentially even implants, and the application of facial recognition systems in the laboratory can offer further tailoring of information to specific individuals and compliance monitoring, especially when combined with the Internet of Chemical Things.…”