Cationic Cascade for Building Complex Polycyclic Molecules from Simple Precursors: Diastereoselective Installation of Three Contiguous Stereogenic Centers in a One-Pot Process
作者:Georgios Alachouzos、Alison J. Frontier
DOI:10.1021/jacs.8b11713
日期:2019.1.9
Friedel-Crafts allylation. The entire sequence forms three carbon-carbon bonds and a carbon-halogen bond, generating halocyclopentene adducts in one pot from simple precursors. The process occurs with excellent diastereocontrol, providing highly functionalized polycycles containing three tertiary or quaternary stereogenic centers in a linear array. It is even possible to install three contiguous all-carbon quaternary
Copper-Mediated Selective Cross-Coupling of 1,1-Dibromo-1-alkenes and Heteronucleophiles: Development of General Routes to Heterosubstituted Alkynes and Alkenes
site-selective, double, or alkynylative cross-coupling, therefore providing divergent and straightforward entries to numerous building blocks such as bromoenamides, ynamides, ketene N,N-acetals, bromoenol ethers, ynol ethers, keteneO,O-acetals, or vinylphosphonates and further expanding the copper catalysis toolbox with useful and versatile processes.
Synthesis of 1,3-Diynes via Cadiot–Chodkiewicz Coupling of Volatile, in Situ Generated Bromoalkynes
作者:Phil C. Knutson、Haleigh E. Fredericks、Eric M. Ferreira
DOI:10.1021/acs.orglett.8b02975
日期:2018.11.2
A convenient Cadiot–Chodkiewicz protocol that facilitates the use of low molecular weight alkyne coupling partners is described. The method entails an in situ elimination from a dibromoolefin precursor and immediate subjection to copper-catalyzed conditions, circumventing the hazards of volatile brominated alkynes. The scope of this method is described, and the internal 1,3-diyne products are preliminarily
Benzannulation of Triynes to Generate Functionalized Arenes by Spontaneous Incorporation of Nucleophiles
作者:Rajdip Karmakar、Sang Young Yun、Jiajia Chen、Yuanzhi Xia、Daesung Lee
DOI:10.1002/anie.201412468
日期:2015.5.26
The thermal reaction of ester‐tethered 1,3,8‐triynes provides novel benzannulation products with concomitant incorporation of a nucleophile. Evidence suggests that this reaction proceeds via an allene‐enyne intermediate generated by an Alder‐ene reaction in the first step. Depending on the substituent of the alkyne moiety on the allene‐enyne intermediate, the subsequent transformation can take one
Exploiting 1,1-Dibromoalkenes as Direct Precursors to 5-Substituted 1,2,3-Triazoles
作者:Alistair Boyer、Matthew B. Williams、Matthew L. Martin、Steffen Wiedmann
DOI:10.1055/s-0042-1751464
日期:2023.11
precursors to three classes of 5-substituted 1,2,3-triazoles. Three different approaches to 1,2,3-triazole products were developed, linked to the N1-substituent. Treatment of 1,1-dibromoalkenes with n-butyllithium and reaction with a sulfonyl azide gave 5-substituted 1-sulfonyl-1,2,3-triazoles. The use of lithium base followed by transmetalation to zinc and reaction with aryl azides allowed access