نتایج جستجو برای: heterocycle

تعداد نتایج: 914  

Journal: :ACS Catalysis 2021

The combination of nucleophilic nitrenoids and ?-acid catalysis has emerged as a powerful tool in heterocycle synthesis. Accessing more varied heterocycle-substitution patterns by maintaining the same reaction pathways across different alkynes remains challenge. Here we show that Au(I) isoxazole-based with alkynyl thioethers provides controlled access to (3 + 2) annulation regioselective additi...

Journal: :The Journal of organic chemistry 2002
Leonid Breydo Kent S Gates

Reaction of thiols with the 1,2-dithiolan-3-one 1-oxide heterocycle found in leinamycin (1) results in the conversion of this antitumor antibiotic to a DNA-alkylating episulfonium ion (5). While the products formed in this reaction have been rationalized by a mechanism involving initial attack of thiol on the central sulfenyl sulfur (S2') of the 1,2-dithiolan-3-one 1-oxide ring, the carbonyl ca...

Journal: :Physical Review Letters 2004

2015
Egija Stepina Dmitrijs Stepanovs Inese Mierina Mara Jure

The title compound, C17H21NO4, consists of substituted Meldrum's acid with a [4-(di-ethyl-amino)-phen-yl]methyl-idene fragment attached to the fifth position. The heterocycle assumes a distorted boat conformation. The planar part of heterocycle is almost coplanar with the benzene ring due to the presence of a long conjugated system in the mol-ecule. This leads to the formation of C-H⋯O-type int...

Journal: :Organic & biomolecular chemistry 2010
Mark G Simpson Michael Pittelkow Stephen P Watson Jeremy K M Sanders

We expand the possibilities in hydrazone based dynamic combinatorial chemistry with a series of new building blocks incorporating heterocyclic motifs. The synthetic procedure allows efficient access to building blocks with the general structure (MeO)(2)CH-Heterocycle-C(O)NHNH(2), originating from heterocycles with an amine and an ester functionality. The equilibrium distribution of macrocyclic ...

2009
Markus Nahrwold Arvydas Stončius Anna Penner Beate Neumann Hans-Georg Stammler Norbert Sewald

Novel procedures have been developed to condense benzaldehyde effectively with beta-amino acid amides to cyclic benzyl aminals. Double carbamate protection of the heterocycle resulted in fully protected chiral beta-alanine derivatives. These serve as universal precursors for the asymmetric synthesis of functionalised beta(2)-amino acids containing acid-labile protected side chains. Diastereosel...

2017
Andrew J Capel Andrew Wright Matthew J Harding George W Weaver Yuqi Li Russell A Harris Steve Edmondson Ruth D Goodridge Steven D R Christie

Additive manufacturing or '3D printing' is being developed as a novel manufacturing process for the production of bespoke micro- and milliscale fluidic devices. When coupled with online monitoring and optimisation software, this offers an advanced, customised method for performing automated chemical synthesis. This paper reports the use of two additive manufacturing processes, stereolithography...

2010
Gholamhossein Mohammadnezhad Ali Reza Ghanbarpour Mostafa M. Amini Seik Weng Ng

In the centrosymmetric binuclear title compound, [Pb(2)(N(3))(2)(NCS)(2)(C(12)H(8)N(2))(4)], the N-donor atoms of one N-heterocycle and the N-donor atom of a thio-cyanate anion along with the sterically active lone-pair electrons comprise an approximate square; a plane through three atoms of this square is twisted slightly with respect to the square made up of the other four atoms (two from the...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید