Results 61 to 70 of about 22,823 (226)

Cyclobutanes in Small‐Molecule Drug Candidates

open access: yesChemMedChem, 2022
AbstractCyclobutanes are increasingly used in medicinal chemistry in the search for relevant biological properties. Important characteristics of the cyclobutane ring include its unique puckered structure, longer C−C bond lengths, increased C−C π‐character and relative chemical inertness for a highly strained carbocycle.
Marnix R. van der Kolk   +3 more
openaire   +4 more sources

Methyl on the Bridge: 2‐Methyl Propellane as Precursor for 1,3‐Substituted 2‐Methylated Bicyclo[1.1.1]Pentanes

open access: yesChemistry – A European Journal, EarlyView.
The synthesis of 2‐methyl propellane and its conversion to various 1,2‐ and 1,2,3‐di‐ and trisubstituted bicyclopentanes is reported. Abstract Bicyclo[1.1.1]pentanes (BCPs) have emerged as isosteric replacements for mono‐ and para‐substituted benzene rings in medicinal and materials applications, involving substitution at the BCP bridgehead (1,3 ...
Sean R. Verschaeve   +4 more
wiley   +1 more source

Asymmetric Hydrogenation in Water by a Rhodium Complex of Sulfonated 2,2'-Bis(diphenylphosphino)-1,1'-binaphthyl (binap) [PDF]

open access: yes, 1993
The synthesis of sulfonated 2,2′-bis(diphenylphosphino)-1,1′-binaphthyl (binap) is reported; a rhodium complex of this ligand is the first to perform asymmetric hydrogenation in neat water with optical yields as high as those obtained in nonaqueous ...
Davis, Mark E., Wan, Kam-to
core   +1 more source

Light‐Induced Reactions of Small‐Membered Cyclic Carbonyl Compounds

open access: yesEuropean Journal of Organic Chemistry, EarlyView.
This review highlights recent advances in the synthesis and photochemical reactivity of cyclopropenone and cyclobutenedione. These compounds undergo photolysis upon direct excitation, and in some cases, through indirect excitation by photocatalysts. The resulting photogenerated species exhibit unique reactivity profiles that are strongly influenced by ...
Kenji Mishiro
wiley   +1 more source

Preparation of Enantioenriched Spirocyclic Scaffolds Transferring Axial Chirality from Borylalkylidenecycloalkanes

open access: yesChemistryEurope
Herein, an efficient transference of axial chirality from enantiomerically enriched borylalkylidenecycloalkanes to point chirality is disclosed through the synthesis of spirocyclic valuable compounds via cyclopropanation, borylcyclopropanation ...
Nerea Iragorri   +4 more
doaj   +1 more source

r-1,t-3-Bis[4-(dimethylamino)phenyl]-c-2,t-4-bis(pyridin-4-yl)cyclobutane

open access: yesActa Crystallographica Section E, 2014
The title compound, C30H32N4, was synthesized by the photodimerization of trans-4-{2-[4-(dimethylamino)phenyl]ethenyl}pyridine in benzene upon irradiation with UV light.
Shuguang Zhang, Junpeng Zhuang
doaj   +1 more source

Formal Synthesis of the Akuammiline Alkaloid (±)‐Strictamine via a (4 + 2) Annulation Reaction With a Donor–Acceptor Cyclobutane

open access: yesHelvetica Chimica Acta, EarlyView.
We report a concise formal synthesis of (±)‐strictamine via a silylium‐catalyzed (4 + 2) annulation of a donor–acceptor cyclobutane, achieved in 13 steps from tryptamine. ABSTRACT The akuammiline alkaloids are complex monoterpene indole natural products with a rigid cage‐like architecture and diverse biological activities.
Clément Tanguy   +2 more
wiley   +1 more source

[3-Benzoyl-2,4-bis(3-nitrophenyl)cyclobutyl](phenyl)methanone

open access: yesActa Crystallographica Section E, 2012
The asymmetric unit of the title compound, C30H22N2O6, comprises a half-molecule of the cyclobutane derivative. The least-squares planes defined by the respective C atoms of the aromatic substituents intersect at angles of 76.81 (7) and 89.22 ...
Prakash S. Nayak   +5 more
doaj   +1 more source

Electron Donor–Acceptor Complexes Without Preinstalled Sacrificial Leaving Groups: Applications in Synthesis

open access: yesHelvetica Chimica Acta, EarlyView.
Leaving‐group–free electron donor–acceptor (EDA) complexes have emerged as a practical platform for photocatalyst‐free radical generation under visible light. This review highlights recent advances in coupling and cyclization reactions driven by such EDA complexes, emphasizing their atom‐economical and sustainable feature.
Wenheng Liu, Line Næsborg
wiley   +1 more source

[2+2]-Photocycloadditions of 2-Acetoxy-1,4-naphthoquinone and Structure Determination of the Main Photoadducts

open access: yesPhotochem
The [2+2]-photocycloaddition of 2-acetoxy-1,4-naphthoquinone with 1,1-diphenylethylene, styrene and cyclopentene was conducted in a conventional batch reactor.
Madyan A. Yaseen   +3 more
doaj   +1 more source

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