The synthesis of 3-(aminoalkyl)coumarins starting with a platinum/scandium-cocatalyzed oxidative dehydrogenation of α,β-C(sp(3))-H bonds of tertiary amines in the presence of ambient oxygen followed by reactions with substituted salicylaldehydes is revealed. The in situ formed enamines reacted with various salicylaldehydes, which resulted in the development of a one-pot synthetic protocol involving aldol reaction, cyclization, and then ring-opening.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/jo102219z | DOI Listing |
Org Lett
January 2025
College of Materials and Energy, South China Agricultural University, 510642 Guangzhou, China.
We report herein a robust enantioselective ring opening coupling of oxabenzonorbornadienes via Pd(II)-catalyzed domino cyclization of alkynylanilines, which features the formation of three covalent bonds and two contiguous stereocenters with excellent enantio- and diastereoselectivity and a broad substrate scope. The good functional group tolerance of this domino desymmetrization strategy enables efficient late-stage transformation of natural product-derived alkynylanilines. The resulting indolated dihydronaphthols could serve as a valuable platform to streamline the diversity-oriented synthesis of other valuable enantioenriched tetrahydronaphthalene derivatives.
View Article and Find Full Text PDFChemistryOpen
December 2024
MTA TTK Lendület Artificial Transporter Research Group, Institute of Materials and Environmental Chemistry, HUN-REN Research Center for Natural Sciences, H-1117, Budapest, Magyar tudósok krt. 2, Hungary.
Novel tetrahydroisoquinoline and piperidine derivatives were selectively synthesized from substituted indenes or cyclopentenes. The process starts with an oxidative cleavage of the ring olefin bond, which gives reactive diformyl intermediates. By a ring-closing step using chiral (R) or (S) α-methylbenzylamine under a reductive amination protocol facilitated ring formation with ring expansion of the corresponding nitrogen-containing heterocycles.
View Article and Find Full Text PDFNature
December 2024
Department of Chemistry, University of Basel, Basel, Switzerland.
Aromatic compounds are used across chemistry and materials science as a result of their stability, characteristic interactions, defined molecular shape and the numerous synthetic approaches for their synthesis by a diversity of cyclization reactions. In contrast, the cleavage of inert aromatic carbon-carbon bonds remained largely unfeasible due to the unfavourable energetics of disrupting aromaticity on ring opening. For non-aromatic structures, alkene metathesis catalysed by transition metal alkylidenes is established as one of the most versatile carbon-carbon bond-forming and breaking reactions.
View Article and Find Full Text PDFOrg Lett
December 2024
Key Laboratory of the Ministry of Education for Advanced Catalysis Materials, College of Chemistry and Materials Science, Zhejiang Normal University, 688 Yingbin Road, Jinhua 321004, China.
An unexpected cascade reaction of enyne-amides with sulfur-ylides has been developed. This cascade reaction involves cycloisomerization, dearomatic cyclopropanation, ring-opening rearomatization, and subsequent cyclopropanation, differing from the common [2 + n] cyclization of enyne-amides. A variety of (spirocyclopropane)dihydrofuran derivatives have been efficiently and conveniently synthesized in a single vessel, exhibiting excellent diastereoselectivity and good functional group tolerance.
View Article and Find Full Text PDFJ Am Chem Soc
December 2024
Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States.
In this report, we detail two distinct synthetic approaches to calyciphylline A-type alkaloids himalensine A and daphenylline, which are inspired by our analysis of the structural complexity of these compounds. Using MolComplex, a Python-based web application that we have developed, we quantified the structural complexity of all possible precursors resulting from one-bond retrosynthetic disconnections. This led to the identification of transannular bonds as especially simplifying to the molecular graph, and, based on this analysis, we pursued a total synthesis of himalensine A from macrocyclic intermediates with planned late-stage transannular ring formations.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!