Ordered short channel mesoporous silica modified with 1,3,5-triazine–piperazine as a versatile recyclable basic catalyst for cross-aldol, Knoevenagel and conjugate addition reactions with isatins
作者:Naveen Gupta、Tamal Roy、Debashis Ghosh、Sayed H. R. Abdi、Rukhsana I. Kureshy、Noor-ul H. Khan、Hari C. Bajaj
DOI:10.1039/c5ra00406c
日期:——
A recyclable triazine–piperazine immobilized silica supported material was explored as a heterogeneous catalyst for indole skeletal synthesized from isatins at RT.
A chiralsecondaryaminephosphoramide was developed and identified as a powerful catalyst for the Mukaiyama–Michael addition of fluorinatedenolsilylethers to tetrasubstituted olefins. The resulting products are obtained with high enantioselectivities and contain a quaternarycarbonstereocenter bearing either a difluoroalkyl or monofluoroalkyl group.
Synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives <i>via</i> a multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate
作者:Taoda Shi、Shenghan Teng、Yajie Wei、Xin Guo、Wenhao Hu
DOI:10.1039/c9gc01751h
日期:——
We report a green synthesis of spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives which are of potential value in medicinal chemistry. We are able to access spiro[2,3-dihydrofuran-3,3′-oxindole] derivatives via a Cu(OTf)2-catalyzed or Cu(OTf)2/Rh2(OAc)4-cocatalyzed multi-component cascade reaction of α-diazo esters, water, isatins and malononitrile/ethyl cyanoacetate. The reaction can be accomplished
Organocatalytic Enantioselective 1,3-Dipolar Cycloadditions between Seyferth–Gilbert Reagent and Isatylidene Malononitriles: Synthesis of Chiral Spiro-phosphonylpyrazoline-oxindoles
作者:Taiping Du、Fei Du、Yanqiang Ning、Yungui Peng
DOI:10.1021/acs.orglett.5b00311
日期:2015.3.6
A new method has been developed for the catalytic enantioselective 1,3-dipolar cycloaddition of the Seyferth–Gilbert reagent (SGR) to isatylidene malononitriles using a cinchonaalkaloidderivative as a catalyst. This method allowed for the synthesis of a series of chiral spiro-phosphonylpyrazoline-oxindoles in good yields with excellent enantioselectivities. The synthetic utility of this method was
Organocatalytic enantioselective conjugate addition of ketones to isatylidine malononitriles
作者:Lu Liu、Deyan Wu、Xiangmin Li、Sinan Wang、Hao Li、Jian Li、Wei Wang
DOI:10.1039/c2cc17067a
日期:——
An enantioselective Michael addition of ketones to alkylidenemalononitriles catalyzed by chiral primary amine I with (R)-5c as a co-catalyst in good yields (>90%) and with good enantioselectivities (85–96% ee) has been developed. The strategy has also been extended to a three-component version through a domino Knoevenagel/Michael sequence with similar or better outcomes.