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
Transition metal‐catalyzed [2+2+2] cyclotrimerization is a powerful method to synthesize substituted benzene derivatives with optimal atom efficiency. However, controlling regio‐ and chemoselectivity is difficult. We present a cobalt catalyzed cycloaddition of alkynes, which provides the cycloaddition products in high yields and excellent regioselectivity in the presence of a pyridine‐2,6‐diimine ligand
The photochemically initiated dehydro-Diels-Alder (PDDA) reaction is an efficient and versatile method for the prepa- ration of biaryls. The ring closure may take place both inter- and in- tramolecularly, of which the intramolecular variant is more productive from the preparative point of view. A variety of linkers can be employed to connect the ynone moiety, which acts as the chromophore, with another
Organocatalytic
<i>Trans</i>
Semireduction of Primary and Secondary Propiolamides: Substrate Scope and Mechanistic Studies
作者:R. Justin Grams、Monsurat M. Lawal、Connor Szwetkowski、Daniel Foster、Carol Ann Rosenblum、Carla Slebodnick、Valerie Vaissier Welborn、Webster L. Santos
DOI:10.1002/adsc.202101020
日期:2022.1.4
We report a chemoselective, phosphine-catalyzed semireduction of primary and secondary propiolamides. In the presence of stoichiometric pinacolborane and catalytic n-tributylphosphine, a variety of propiolamides were successfully converted to the corresponding acrylamides in excellent yield with (E)-stereoselectivity. The reaction condition is tolerant of various functional groups including alkene
我们报告了初级和次级丙酰胺的化学选择性、膦催化的半还原反应。在化学计量的频哪醇硼烷和催化正三丁基膦的存在下,各种丙酰胺以优异的收率成功转化为相应的丙烯酰胺,具有(E)-立体选择性。反应条件可以容忍各种官能团,包括烯烃、炔烃、酮或酯。氘标记研究表明,来自活化频哪醇硼烷的氢化物被添加到 α-碳,酰胺氮上的质子被 β-碳提取以提供 ( E )-丙烯酰胺。DFT 计算揭示了 ( E )- 在 ( Z)-异构体。
Organocatalyzed carboxylative cyclization of propargylic amides with atmospheric CO<sub>2</sub> towards oxazolidine-2,4-diones
作者:Hui Zhou、Sen Mu、Bai-Hao Ren、Rui Zhang、Xiao-Bing Lu
DOI:10.1039/c8gc03929a
日期:——
The metal-free carboxylative cyclization of propargylicamides with CO2 to oxazolidine-2,4-diones was achieved for the first time employing 1,5,7-triaza-bicyclo-[4.4.0]dec-5-ene (TBD) as an organocatalyst. This method allows for the efficient and selective synthesis of a variety of (Z) 5-alkylidene 1,3-oxazolidine-2,4-diones, and a variety of functional groups are well-tolerated under mild reaction