Results 51 to 60 of about 6,473 (220)

Unified Synthesis of Unconventional α‐Polyhalogenated Amines Through Hydroaminoalkylation

Angewandte Chemie International Edition, EarlyView.
A unified, redox‐neutral method that transforms alkenes and alkynes into α‐polyhalomethyl amines using stable hemiaminal reagents is reported. This approach enables access to CF3, CF2H, CF2Cl, and CFClH motifs, expanding halogenated amine space with broad substrate scope, functional group tolerance, and applicability to late‐stage modification of drug ...
Angela K. Hofmeister, Giulia Iannelli, Péter Angyal, Augustin Malandain, Daniel Kaiser, Boris Maryasin, Hanspeter Kählig, Matteo Barel, Gaia Novarino, Nuno Maulide   +9 more
wiley   +1 more source

Diastereoselective Formation of Complexed Methylenediphosphiranes [PDF]

Organometallics, 2008
Stable syn-substituted methylenediphosphirane complexes are obtained from the reaction of transient, electrophilic phosphinidenes [R-P=W(CO)
Jansen, Helen, Rosenthal, A.J., Slootweg, J.C., Ehlers, A.W., Lutz, M., Spek, A.L., Lammertsma, K.   +6 more
openaire   +4 more sources

Highly Enantio‐ and Diastereoselective Synthesis of Tetrahydrofuran Frameworks via Chiral Lewis Acid‐Catalyzed Formal [3+2] Cycloaddition of Allylsilanes

Angewandte Chemie International Edition, EarlyView.
The first catalytic asymmetric formal [3+2] cycloaddition of allylsilanes delivers cis‐2,5‐disubstituted tetrahydrofuran‐3‐ones that serve as versatile intermediates for the synthesis of diverse bioactive scaffolds. ABSTRACT A formal [3+2] cycloaddition via cyclization/1,2‐hydride shift initiated by nucleophilic attack of allylsilanes has been ...
Hosung Lee, Dong Kyu Kim, Pingshan Xin, Jin Won Lee, Terim Seo, Do Hyun Ryu   +5 more
wiley   +1 more source

Triphenylmethyl Group as a Highly Diastereoselective exo,endo-Auxiliary in Double Diels–Alder Reactions with 2H-Pyran-2-ones

Molecules
The influence of steric hindrance caused by the dienophiles on the stereoselectivity of cycloadditions of 2H-pyran-2-ones with maleimides was investigated in this study.
Marko Krivec, Žiga Štirn, Marijan Kočevar, Krištof Kranjc   +3 more
doaj   +1 more source

Photogenerated Oxetanes as a Gateway to Uphill Cyclopropanation

Angewandte Chemie International Edition, EarlyView.
An atom‐economical route to densely functionalized cyclopropanes from furans and photochemically activated aldehydes is enabled by a unique oxetane‐to‐cyclopropane rearrangement. These cyclopropanes can be used to access complex bioactive scaffolds and serve as a platform for asymmetric cyclopropane synthesis.
Tim Köglmeier, Thomas J. Tiefel, Oliver Reiser   +2 more
wiley   +1 more source

An efficient synthesis of the guaiane sesquiterpene (−)-isoguaiene by domino metathesis

Beilstein Journal of Organic Chemistry, 2019
(−)-Isoguaiene was prepared from (S)-citronellal in only 9–10 steps with good overall yields. Either a trienyne or a dienediyne metathesis and highly diastereoselective organocatalytic Michael additions of aldehydes derived from (S)-citronellal served as
Yuzhou Wang, Ahmed F. Darweesh, Patrick Zimdars, Peter Metz   +3 more
doaj   +1 more source

Diastereoselective Spiroannulation of Phenolic Derivatives: Effect of Steric Hindrance on the Diastereoselectivity

International Journal of Chemistry, 2011
This study was aimed at determining the effect, if any, that steric factors may have on the diastereoselectivity in the spiroannulation of simple phenols. A series of phenols bearing different size substituents ortho to the phenolic hydroxyl were synthesized and spiroannulated to the corresponding spiroethers in good to excellent yields (76-94 ...
Guy L Plourde, Lyndia M. Susag
openaire   +2 more sources

Fluorine‐Directed Diastereoselective Iodocyclizations

Angewandte Chemie International Edition, 2007
An inside job: β‐Fluorinated lactones and tetrahydrofurans are synthesized by iodocyclization of various allylic fluorides. The fluorine substituent acts as a highly efficient syn‐stereodirecting group for the ring closure. The experimental results combined with theoretical studies provide evidence in support of an “inside fluoro effect” to account for
Tredwell, M, Luft, J, Schuler, M, Tenza, K, Houk, K, Gouverneur, V   +5 more
openaire   +2 more sources

Diastereoselection:  Introduction [PDF]

Chemical Reviews, 1999
B W, Gung, B, le Noble
openaire   +2 more sources

Total Asymmetric Synthesis of Glycomimetics and Polypropionates of Biological Interest

CHIMIA, 2008
Using readily available chiral auxiliaries such as (+)- and (?)-camphanic acid, (R,R)- and (S,S)-tartaric acid derivatives (e.g. RADO(R)-COCl, SADO(R)-COCl) efficient diastereoselective syntheses of rare sugars and glycomimetics have been ...
Pierre Vogel
doaj   +1 more source