An unprecedented boron-containing fluorophore, π-extended cis-stilbene, obtained via alkynylboration reaction of alkynamide is reported. Boron-containing π-extended cis-stilbenes emit fluorescence with high quantum yields in the solid state and exhibit aggregation-induced emission enhancement. The broad substrate scope of the alkynylboration reaction offers facile access to electronically diverse structures
Cationic Rhodium(I)-Catalyzed Regioselective Tandem Heterocyclization/[3+2] Cycloaddition of 2-(1-Alkynyl)-2-alken-1-ones with Alkynes
作者:Hongyin Gao、Junliang Zhang
DOI:10.1002/chem.201103924
日期:2012.3.5
RhI in two minds: A RhI‐catalyzed tandem heterocyclization/[3+2] cycloaddition reaction was developed that provides rapid, efficient, and stereoselective access to highly substituted cyclopenta[c]furans from readily available 2‐(1‐alkynyl)‐2‐alken‐1‐ones and alkynes (see scheme). The cationic RhI acts as both a Lewis acid and a conventional transition‐metal catalyst, providing the first example of
We found that the combination of [Ir(cod)Cl]2 and rac-BINAP served as an efficient catalyst for the [2+2+2] cycloaddition of 2,7-nonadiyne derivatives and related compounds with alkynyl ketones and alkynyl esters. The corresponding products were obtained in high yields under mild reaction conditions.
Transition Metal-Free <i>Trans</i> Hydroboration of Alkynoic Acid Derivatives: Experimental and Theoretical Studies
作者:Russell Fritzemeier、Ashley Gates、Xueying Guo、Zhenyang Lin、Webster L. Santos
DOI:10.1021/acs.joc.8b01493
日期:2018.9.7
(E)-β-boryl acrylamides in good to excellent yields. The reaction is tolerant of a variety of functional groups and allows efficient access to novel oxaboroles as well as a pargyline derivative (MAO inhibitor). Theoretical calculations suggest an internal hydride generates a phosphonium allenoxyborane followed by the formation of a key phosphonocyclobutene intermediate that collapses in a stereoselective
<i>trans</i>-Hydroboration of Propiolamides: Access to Primary and Secondary (<i>E</i>)-β-Borylacrylamides
作者:R. Justin Grams、Russell G. Fritzemeier、Carla Slebodnick、Webster L. Santos
DOI:10.1021/acs.orglett.9b02408
日期:2019.9.6
A base-mediated trans-hydroboration of propiolamides that provides access to previously elusive primary and secondary (E)-β-borylacrylamide products has been developed. In the presence of n-butyllithium and pinacolborane, complete regioselectivity and stereoselectivity is observed, affording the corresponding vinylboronate products in up to 91% yield. A wide variety of primary and secondary amides