Reactions and diastereoselectivity of N2-arylsulfonyl amidine anions
摘要:
Cyclic N1-alkyl-N2-sulfonyl amidine anions undergo stereoselective aldol reactions to give the syn diastereoisomer as the major product. The ratio of syn to anti aldol products decreases as the size of the N1-alkyl increases. This is interpreted as a change in the transition state from an open-aldol to a closed-Zimmerman-Traxler-type transition state.
A direct and convenient metal-free method to prepare sulfonyl amidines in the presence of aqueous tert-butyl hydroperoxide (T-HYDRO) has been developed. Different tertiary and secondary amines were tested for compatibility with the oxidative conditions and could be coupled with sulfonyl azides to form the corresponding amidines in moderate to good yields.
Visible-Light-Mediated Sulfonylimination of Tertiary Amines with Sulfonylazides Involving C<sub>sp<sup>3</sup></sub>–C<sub>sp<sup>3</sup></sub> Bond Cleavage
作者:Jiao Gui、Haisheng Xie、Huanfeng Jiang、Wei Zeng
DOI:10.1021/acs.orglett.9b00786
日期:2019.4.19
Visible-light-induced cross-coupling of arylsulfonyl azides with tertiaryamines in the presence of Eosin Y at room temperature has been achieved. This transformation features alkyl C–C bond cleavage and provides a green approach to N-sulfonylamidines under mild conditions.
Synthesis of Cyclic Amidines by Iridium-Catalyzed Deoxygenative Reduction of Lactams and Tandem Reaction with Sulfonyl Azides
作者:Youliang He、Xiaoming Wang
DOI:10.1021/acs.orglett.0c03953
日期:2021.1.1
An efficient and convenient synthesis of various cyclic amidines has been achieved via iridium-catalyzed deoxygenative reduction of lactams with a silane followed by a one-pot cycloaddition reaction with sulfonyl azides. Using the novel tandem procedure, a large array of cyclic amidines bearing various sized rings were synthesized in good yields from readily available lactams. This methodology has
Interception of amide ylides with sulfonamides: synthesis of (<i>E</i>)-<i>N</i>-sulfonyl amidines catalyzed by Zn(OTf)<sub>2</sub>
作者:Jijun Chen、Wenhao Long、Shangwen Fang、Yonggang Yang、Xiaobing Wan
DOI:10.1039/c7cc07364j
日期:——
Through the interception of amide ylides with sulfonamides, we herein report the first general example of an intermolecular condensation reaction between sulfonamides and amides. Beyond formamides, this approach was successfully applied to a variety of lactams and linear amides, giving rise to a broad array of (E)-N-sulfonyl amidines.