School of Cancer and Pharmaceutical Sciences, King's College London, 150 Stamford Street, SE1 9NH, London, UK.
Published: January 2021
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Article Abstract
A mild, chemoselective and sustainable biocatalysed synthesis of sulfoxides has been developed exploiting CALB and using AcOEt with a dual role of more environmentally friendly reaction solvent and enzyme substrate. A series of sulfoxides, including the drug omeprazole, have been synthesised in high yields and with excellent E-factors.
The synthetic utility of tetrabenzyl pyrophosphate for achieving chemoselective phosphorylation of phenols, as well as primary, secondary, and tertiary alcohols, is reported here. Additionally, we introduce a rapid, mild, and chemoselective debenzylation procedure, enabling access to phosphates in the presence of redox sensitive groups. Finally, stoichiometrically controlled monodebenzylation provides a versatile platform for late-stage divergent synthesis of phosphodiester and phosphoramidate chemical libraries.
State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin 541004, China.
A visible light-driven, intermolecular interrupted Barton reaction has been developed for radical-relay sulfonyloximation of alkenes with alkyl nitrites, using DABSO as a trapping reagent. This method overcomes the challenges of competing normal Barton reactions and polarity mismatches by rapidly and irreversibly capturing alkyl radicals, preventing unwanted side reactions. The resulting polarity-reversed sulfonyl radicals undergo highly selective addition to alkenes, yielding α-alkylsulfonyl ketoximes tethered to hydroxyl or ketone groups.
A photocatalytic sulfamoylation/5- cyclization of ()-'-arylidene--phenylmethacrylohydrazides with sulfamoyl chlorides was developed. The chemoselective intramolecular addition of the carbon-centered radical intermediate to the CN bond in the hydrazone motif gave the sulfamoylated pyrazolin-5-one. Besides, sulfonyl chlorides are also suitable reaction partners to access sulfonylated pyrazolin-5-ones.
In this study, a metal-free and efficient method for the synthesis of sulfilimines and -sulfanylanilines in high yields with excellent chemoselectivities from oxonium aryne precursors with sulfenamides has been developed. This method features mild reaction conditions, simple operations, a general substrate scope, and good tolerance of functional groups. In addition, scale-up synthesis, related applications, and preliminary mechanistic explorations were also investigated.
State Key Laboratory of Coordination Chemistry, Engineering Research Center of Photoresist Materials, Ministry of Education, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, 210093, Nanjing, China.
Divergent catalysis represents an exciting frontier for unlocking molecular structural diversity and exploring new activation modes. Here, we report the unexpected discovery of polarity-reversed divergent activation and functionalization of aliphatic aldehydes, where enolizable aliphatic aldehydes are selectively activated by nickel hydride to form two distinct alkylnickel intermediates divergently. This mild and operationally simple process enables the transformation of a wide variety of readily available aliphatic aldehydes, along with alkyl or aryl electrophiles, into the corresponding secondary alcohols or more challenging deoxygenated alkanes with excellent chemoselectivity.
