Search results for "combinatorial"
showing 10 items of 1208 documents
ChemInform Abstract: Synthesis of 3-Substituted Isoindolin-1-ones via a Tandem Desilylation, Cross-Coupling, Hydroamidation Sequence under Aqueous Ph…
2016
A simple and expedient method for the synthesis of 3-methylene-isoindolin-1-ones 4 under aqueous phase-transfer conditions has been developed. Starting from 2-iodobenzamides 1 and (silyl)alkynes, the products are obtained in high yields and short reaction times (30 min) with the use of inexpensive CuCl/PPh3 catalyst system in the presence of n-Bu4NBr (TBAB) as a phase-transfer agent. Terminal alkynes are conveniently “unmasked” upon in situ desilylation under the reaction conditions. Alkynes possessing heterocyclic moieties were also found as amenable substrates. Furthermore, a one-pot process starting from 2-iodobenzamides 1, aryl halides (bromides or iodides) and trimethylsilylacetylene (…
ChemInform Abstract: Organocatalytic Enantioselective Synthesis of Pyrazoles Bearing a Quaternary Stereocenter.
2016
An efficient one-pot asymmetric synthesis of pyrazoles bearing a chiral quaternary stereocenter has been developed. Quinine-derived thiourea catalyzed the enantioselective addition of pyrazolones to isatin-derived ketimines, providing the corresponding acetylated pyrazoles after in situ treatment with Ac2 O/Et3 N. The corresponding pyrazoles were afforded in high yields and excellent enantioselectivities.
A Straightforward Route to Homoallyl-Homocrotylamines Promoted by a Titanium Complex
2012
I�-Allyltitanium complexes, generated in situ from 1,3-dienes and Cp2TiH, react with benzotriazole derivatives to give homoallylic amines in good yields. Under similar conditions, triple cascade reactions (allyltitanation followed by cationic 2-aza-Cope rearrangement followed by a second allyltitanation) occur from bis(benzotriazolyl) compounds affording a straightforward route to homoallyl-(E)-homocrotylamines. A theoretical study provides further insight into the factors that govern the selectivity of this sequence of reactions. The titanium-promoted reductive coupling of 1,3-dienes with bis(benzotriazolyl) compounds as substrates led selectively to homoallyl-homocrotylamines through a tr…
ChemInform Abstract: Dual Hydrogen-Bond/Enamine Catalysis Enables a Direct Enantioselective Three-Component Domino Reaction.
2011
A dual system, composed of an enantioselective enamine catalyst and a multiple-hydrogen-bond catalyst achieves the three-component enantioselective aldehyde—nitroalkene—aldehyde domino reaction using either two similar or two different aldehydes.
Synthesis of Functionalized 1‐Aryl‐3‐phenylthiazolylpropanoids and Their Potential as Anticancer Agents
2020
ChemInform Abstract: A New Route to Chiral Calix(4)arenes via 1,3-Derivatization.
2010
1,3-Di(hetero)aryl-7-substituted Pyrenes—An Undiscovered Area of Important Pyrene Derivatives
2019
Despite the pyrene derivatives have been covered extensively by scientists during the last years, many interesting properties and applications of pyrene derivatives have been presented, nowadays there are still areas of pyrenes’ chemistry that need to be fulfilled. Most of the described in literature pyrenes are 1,3,6,8-tetrasubstituted followed by 4,5,9,10-tetrasubstituted, 2,7-, and 1,6-, and 1,8-disubstituted pyrene derivatives. In the case of 1,3-di(hetero)aryl-7-substituted, there are only a few examples of derivatives containing at position 7 - tert-butyl group. In this work, the necessity of synthesis of 1,3-di(hetero)aryl-7-substituted pyrenes is presented based on the results of th…
Synthesis of small carboranylsilane dendrons as scaffolds for multiple functionalizations.
2006
Small carbosilane dendrons in which a closo-carborane is located at the focal point have been prepared by a sequence of steps involving hydrosilylation and reduction reactions. These compounds are used as scaffolds for peripheral functionalization with styrene, chlorovinylstyrene, or suitable carboranes, while keeping the C(cluster)-Si (C(c)-Si) bond. Modification of the core by reduction of the carborane with Mg/BrCH2CH2Br was also achieved.
ChemInform Abstract: An Efficient Method for the Preparation of Antitumoral α-Keto-imines Benzyldihydroisoquinolines by Selective Benzylic Oxidation …
2010
A series of potent antitumor α-keto-imine BDHIQ derivatives were synthesized and assayed in vitro against L1210 leukemia cell line. A new and easy method for the direct formation of α-keto-imine from imine BDHIQ's was performed with 10% C/Pd in acetonitrile.
Selectively Functionalized Constrained Polyazamacrocycles: Building Blocks for Multifunctional Chelating Agents
2013
A new class of cross-bridged and side-bridged 1,4,7,10-tetraazacyclotridecanes (homocyclens) bearing an aminomethyl pendant arm on the carbon skeleton has been prepared. The regioselectivity of the quaternization of the bis-aminal intermediates is discussed on the basis of X-ray diffraction and NMR experiments. These new polyazamacrocycles are valuable precursors of bifunctional chelating agents for applications in nuclear medicine.