Rongalite
has been used in several challenging synthetic transformations
with operationally simple and effective protocols. However, the employment
of multiple characteristics of rongalite in synthetic chemistry is
comparatively little known. Herein we report a separate-embedding
type sulfonylmethylation of sulfoxonium ylides in which rongalite
concurrently acted as a sulfone source, C1 synthon, radical initiator,
and potential reducing reagent for the first time. Notably, this facile
and easy-handling reaction does not require a catalyst or prefunctionalized
sulfonylmethylation reagents.
Tropomyosin receptor kinase (TRK) inhibition is an effective therapeutic approach for treatment of a variety of cancers. Despite the use of first-generation TRK inhibitor (TRKI) larotrectinib (1) resulting in significant therapeutic response in patients, acquired resistance develops invariably. The emergence of secondary mutations occurring at the solvent-front, xDFG, and gatekeeper regions of TRK represents a common mechanism for acquired resistance. However, xDFG mutations remain insensitive to second-generation macrocyclic TRKIs selitrectinib (3) and repotrectinib (4) designed to overcome the resistance mediated by solvent-front and gatekeeper mutations. Here, we report the structure-based drug design and discovery of a next-generation TRKI. The structure−activity relationship studies culminated in the identification of a promising drug candidate 8 that showed excellent in vitro potency on a panel of TRK mutants, especially TRKA G667C in the xDFG motif, and improved in vivo efficacy than 1 and 3 in TRK wild-type and mutant fusion-driven tumor xenograft models, respectively.
A concise and efficient hydrodefluorination process was
developed
for the synthesis of gem-difluoroalkenes. This reaction
employs rongalite as a masked proton source and does not require any
additional catalysts or reductants. Notably, trifluoromethyl alkenes
having both terminal and internal double bonds are compatible with
this process, allowing for a wider range of substrates. The successful
late-stage functionalizations of pharmaceuticals and gram-scale syntheses
were used to demonstrate the viability of this method.
An
efficient I2-promoted one-pot one-step three-component
reaction for the synthesis of sulfhydryl indolizines from methyl ketones,
2-pyridylacetate derivatives, and sulfonyl hydrazides via an in situ
cyclization–rethiolation strategy has been developed. This
protocol shows excellent substrate compatibility, including for chain
and cyclic aliphatic methyl ketones, natural product pregnenolone
acetate, and phosphorus-containing methyl ketones, affording a series
of valuable aliphatic-substituted indolizines in good yields.
An
unprecedented [1+1+1+1+1+1] annulation process has been developed
for the construction of tetrahydro-2H-thiopyran 1,1-dioxides.
Notably, rongalite acted as a tethered C–S synthon in this
reaction and can be chemoselectively used as triple C1 units and as
a source of sulfone. Mechanistic investigation indicated that two
different carbon-increasing models are involved in this reaction in
which rongalite serves as C1 units.
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