One-Pot Double-Annulation Strategy for the Synthesis of Unusual Fused Bis-Heterocycles
作者:Shukree Abdul-Rashed、Georgios Alachouzos、William W. Brennessel、Alison J. Frontier
DOI:10.1021/acs.orglett.0c01351
日期:2020.6.5
A novel metal-free double-annulation cascade for the construction of unusual fused heterocyclic systems is described. This simple protocol enables the sequential assembly of two rings in one pot from two simple precursors. Acidic conditions promote the condensation and the intramolecular alkynyl Prins reaction of an enyne or arenyne alcohol with a cyclic hemiaminal to form a five-, six-, or seven-membered
Palladium-Catalyzed Synthesis of Tricyclic Indoles via a N–S Bond Cleavage Strategy
作者:Bo-Sheng Zhang、Fan Wang、Xue-Ya Gou、Ying-Hui Yang、Wan-Yuan Jia、Yong-Min Liang、Xi-Cun Wang、Yuke Li、Zheng-Jun Quan
DOI:10.1021/acs.orglett.1c02715
日期:2021.10.1
bond cleavage with vinyl palladium, thus achieving a highly selective C–N coupling reaction in the Catallani–Lautens reaction system. On the basis of this discovery, a one-step synthesis of highly functionalized tricyclic indole derivatives was realized.
Regioselectivity Influences in Platinum-Catalyzed Intramolecular Alkyne O–H and N–H Additions
作者:Jeff P. Costello、Eric M. Ferreira
DOI:10.1021/acs.orglett.9b03557
日期:2019.12.20
The steric and electronic drivers of regioselectivity in platinum-catalyzed intramolecular hydroalkoxylation are elucidated. A branch point is found that divides the process between 5-exo and 6-endo selective processes, and enol ethers can be accessed in good yields for both oxygen heterocycles. The main influence arises from an electronic effect, where the alkyne substituent induces a polarization
Silver-Catalyzed Enantioselective Propargylic C–H Bond Amination through Rational Ligand Design
作者:Minsoo Ju、Emily E. Zerull、Jessica M. Roberts、Minxue Huang、Ilia A. Guzei、Jennifer M. Schomaker
DOI:10.1021/jacs.0c05726
日期:2020.7.29
precursors from abundant C-H bonds. Herein, we report a regio- and enantioselectivesynthesis of -alkynyl -aminoalcohols via a silver-catalyzed propargylic C-H amination. The protocol was enabled by a new bis(oxazoline) (BOX) ligand designed via a rapid structure-activity relationship (SAR) analysis. The method utilizes accessible carbamateesters bearing -propargylic C-H bonds and furnishes versatile products
Stereochemical Relay through a Cationic Intermediate: Helical Preorganization Dictates Direction of Conrotation in the <i>halo</i>-Nazarov Cyclization
作者:Georgios Alachouzos、Connor Holt、Alison J. Frontier
DOI:10.1021/acs.orglett.0c01330
日期:2020.5.15
halo-Prins/halo-Nazarov cyclization protocol is reported, where chiral information from a secondary alcohol is relayed through several intermediates yielding halocyclopentene products diastereoselectively. An enantiopure product is obtained when a nonracemic secondary alcohol is used. Experimental and computational studies are described, enabling the design and synthesis of systems that ionize and cyclize with >95%