Trityl Isocyanide as a Mechanistic Probe in Multicomponent Chemistry: Walking the Line between Ugi- and Strecker-type Reactions
作者:Răzvan C. Cioc、Hans D. Preschel、Gydo van der Heijden、Eelco Ruijter、Romano V. A. Orru
DOI:10.1002/chem.201600285
日期:2016.6.1
multicomponent chemistry. This reagent can be employed as a cyanide source in the Strecker reaction and as convertible isocyanide in the preparation of N‐acyl amino acids by Ugi 4CR/detritylation and free imidazo[1,2‐a]pyridin‐3‐amines by a Groebke–Blackburn–Bienaymé 3CR condensation/deprotection protocol. The mechanisms of these three classical MCRs intersect at the common N‐trityl nitrilium ion intermediate
α,α′-C–H Bond Difunctionalization of Unprotected Alicyclic Amines
作者:Daniel A. Valles、Subhradeep Dutta、Anirudra Paul、Khalil A. Abboud、Ion Ghiviriga、Daniel Seidel
DOI:10.1021/acs.orglett.1c02187
日期:2021.8.20
A simple one-pot procedure enables the sequential, regioselective, and diastereoselective introduction of the same or two different substituents to the α- and α′-positions of unprotected azacycles. Aryl, alkyl, and alkenyl substituents are introduced via their corresponding organolithium compounds. The scope of this transformation includes pyrrolidines, piperidines, azepanes, and piperazines.
Asymmetric Synthesis of Tetracyclic Pyrroloindolines and Constrained Tryptamines by a Switchable Cascade Reaction
作者:Corien de Graaff、Lisa Bensch、Sjoerd J. Boersma、Răzvan C. Cioc、Matthijs J. van Lint、Elwin Janssen、Nicholas J. Turner、Romano V. A. Orru、Eelco Ruijter
DOI:10.1002/anie.201507041
日期:2015.11.16
The interrupted Fischer indole synthesis of arylhydrazines and biocatalytically generated chiral bicyclic imines selectively affords either tetracyclicpyrroloindolines or tricyclic tryptamine analogues depending on the reaction conditions. We demonstrate that the reaction is compatible with a variety of functional groups. The products are obtained in high optical purity and in reasonable to good yield
α-Functionalization of Cyclic Secondary Amines: Lewis Acid Promoted Addition of Organometallics to Transient Imines
作者:Anirudra Paul、Daniel Seidel
DOI:10.1021/jacs.9b04325
日期:2019.6.5
Cyclic imines, generated in situ from their corresponding N-lithiated amines and a ketone hydride acceptor, undergo reactions with a range of organometallic nucleophiles to generate α-functionalized amines in a single operation. Activation of the transient imines by Lewis acids that are compatible with the presence of lithium alkoxides was found to be crucial to accommodate a broad range of nucleophiles