AlCl3 catalyzed oxa-Diels-Alder reaction of aromatic aldehydes with simple dienes
作者:Wujun Jian、Bo Qian、Hongli Bao、Daliang Li
DOI:10.1016/j.tet.2016.10.049
日期:2017.7
A highly regioselective and diastereoselective oxa-Diels-Alder reaction catalyzed by AlCl3 has been developed. This reaction is efficient and characterized by good functional group compatibility, F, Cl, CN, NO2, OMe and thiophenyl groups are tolerated. A Lewis acid catalyzed concerted cycloaddition mechanism is proposed based on the results.
A New Approach to Non-Coordinating Anions: Lewis Acid Enhancement of Porphyrin Metal Centers in a Zwitterionic Metal–Organic Framework
作者:Jacob A. Johnson、Brenna M. Petersen、Attila Kormos、Elena Echeverría、Yu-Sheng Chen、Jian Zhang
DOI:10.1021/jacs.6b05626
日期:2016.8.17
cationic metal center. We demonstrate the enhanced Lewis acidity of Mn(III)- and Fe(III)-porphyrins in the zwitterionic MOFs in three representative electrocyclization reactions: [2 + 1] cycloisomerization of enynes, [3 + 2] cycloaddition of aziridines and alkenes, and [4 + 2] hetero-Diels-Alder cycloaddition of aldehydes with dienes. This work paves a new way to design functional MOFs for tunable chemical
Scandium(III) Perfluorooctanesulfonate [Sc(OPf)<sub>3</sub>] : A Novel Catalyst for the Hetero Diels–Alder Reaction of Aldehydes with Non-Activated Dienes
Scandium(III) perfluorooctanesulfonate [scandium(III) perflate, Sc(OPf)3] was prepared from either scandium(III) chloride or oxide and perfluorooctanesulfonic acid. The perflate thus obtained acts as a novel Lewis acid catalyst for the intermolecular hetero Diels–Alderreaction of aldehydes with non-activated dienes under mild conditions. The characteristic features of the catalyst include (i) low
Through a kinetically controlled synthetic process, we synthesized PCN-223, a new porphyrinic Zr-MOF constructed from the newly reported hexagonal prismatic 12-connected Zr6 cluster through an unusual disordered arrangement, giving rise to the first example of the shp-a network in MOFs. With its extremely high connectivity, PCN-223 shows high stability in aqueous solutions with a wide range of pH.
Cationic palladium(II) complexes, [PdL2(RCN)2](BF4)2, have been found to catalyze the hetero Diels-Alder reaction of nonactivated simple dienes with aldehydes, affording the corresponding 5,6-dihydro-2H-pyrans in good yields under mild conditions.
发现阳离子钯(II)络合物[PdL 2(RCN)2 ](BF 4)2催化未活化的简单二烯与醛的杂Diels-Alder反应,得到相应的5,6-dihydro-2 H -吡喃在温和条件下收率良好。