Results 61 to 70 of about 19,176 (260)

Synthesis of α-D-GalpN3-(1-3)-D-GalpN3: α- and 3-O-selectivity using 3,4-diol acceptors

Beilstein Journal of Organic Chemistry, 2018
The motif α-D-GalpNAc-(1-3)-D-GalpNAc is very common in Nature and hence its synthesis highly relevant. The synthesis of its azido precursor has been studied and optimized in terms of steps, yields and selectivity. It has been found that glycosylation of
Emil Glibstrup, Christian Marcus Pedersen   +1 more
doaj   +1 more source

Diastereoselective Mannich reactions of pseudo-C2-symmetric glutarimide with activated imines

Beilstein Journal of Organic Chemistry, 2017
As an extension of the boron enolate-based aldol reactions, the oxazolidinone-installed bisimide 1a from 3-(trifluoromethyl)glutaric acid was employed for Mannich reactions with tosylated imines 2 as electrophiles to successfully obtain the corresponding
Tatsuya Ishikawa, Tomoko Kawasaki-Takasuka, Toshio Kubota, Takashi Yamazaki   +3 more
doaj   +1 more source

Catalytic Generation of Cationic Gold Carbene Complexes From 7-Alkynylnorbornadienes and Their Intermolecular Cyclopropanation With Alkenes. [PDF]

Chemistry
Efficient cationic gold(I)‐catalyzed intermolecular cyclopropanation of 7‐alkynylnorbornadiene derivatives has been developed. This methodology offers the synthesis of a new class of norbornene derivatives in high yield with excellent diastereoselectivity.
Ishida K, Toei K, Tomi F, Sakai N.
europepmc   +2 more sources

Diastereoselective synthesis of highly substituted cyclohexanones and tetrahydrochromene-4-ones via conjugate addition of curcumins to arylidenemalonates

Beilstein Journal of Organic Chemistry
A cascade inter–intramolecular double Michael strategy for the synthesis of highly functionalized cyclohexanones from curcumins and arylidenemalonates is reported. This strategy works in the presence of aqueous KOH using TBAB as a suitable phase transfer
Deepa Nair, Abhishek Tiwari, Banamali Laha, Irishi N. N. Namboothiri   +3 more
doaj   +1 more source

Diastereoselective Reformatsky Reaction Mediated by Dichlorocyclopentadienyltitanium(III)

Molecules
The Reformatsky reaction, first reported in 1887, has long been recognized as a fundamental method for carbon–carbon bond construction due to its mild conditions and functional group tolerance. Over the past few decades, this transformation has undergone
Josefa L. López-Martínez, Irene Torres-García, Manuel Muñoz-Dorado, Miriam Álvarez-Corral, Ignacio Rodríguez-García   +4 more
doaj   +1 more source

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

Diastereoselectivity in the alkylations of bicyclic piperidinones

, 1998
The synthesis of substituted [4.3.0] bicyclic lactams derived from 6- oxo-2-hydroxymethylpiperidine is described. The enolate derived flora these systems can be alkylated with a range of reactive electrophiles; the diastereoselectivity which can be ...
Woods, GA, Hermitage, SA, Heightman, TD, Mills, CE, Moloney, MG, Moloney, Mark   +5 more
core   +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

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

pi-Stacking and hydrogen bonding direct diastereoselectivity in one-pot syntheses of octahedral iron(II) complexes

, 2010
One-pot reactions of FeCl(2).4H(2)O and 2,2'-bipyridine-6-carbaldehyde with enantiopure chiral amines lead to octahedral [FeL(2)](2+) complexes, the diastereoselectivity of which depends on the nature of the amine; an interplay of intra-cation pi ...
Constable, E. C., Neuburger, M., Zampese, J. A., Zhang, G., Housecroft, C. E.   +4 more
core   +1 more source