1,1-Disubstituted and trisubstituted alkenes were converted into the corresponding β,γ-unsaturated amines 4 via three steps: the initial formation of α,β-unsaturated diphenylsulfonium triflates 2 from alkenes and diphenyl(trifluoromethanesulfonyloxy)sulfonium trifluoromethanesulfonate (1), followed by double bond migration of 2 to β,γ-unsaturated sulfonium triflates 3 with primary or secondary amines
A One-Pot Iodo-Cyclization/Transition Metal-Catalyzed Cross-Coupling Sequence: Synthesis of Substituted Oxazolidin-2-ones from <i>N</i>-Boc-allylamines
作者:Pauline Chaumont-Olive、Janine Cossy
DOI:10.1021/acs.orglett.0c01114
日期:2020.5.15
metal-catalyzed cross-coupling sequence is reported to access various C5-functionalized oxazolidin-2-onesfrom unsaturated N-Boc-allylamines. Depending on the Grignard reagents used for the cross-coupling, e.g., aryl- or cyclopropylmagnesium bromide, a cobalt or copper catalyst has to be used to obtain the functionalized oxazolidin-2-ones in good yields.
Broadening the Scope of the Zwitterionic 1,3-Diaza-Claisen Rearrangement through a Tethering Strategy
作者:Matthew W. Luedtke、Joseph Pisano、Lucas Paquin、Joel Walker、José S. Madalengoitia
DOI:10.1021/acs.joc.1c00667
日期:2021.6.18
Expansion of the scope of the 1,3-diaza-Claisenrearrangement beyond bridged-bicyclic tertiary allylic amines has been investigated through a tethering strategy. Isothioureas tethered to tertiary allylic amines are converted to carbodiimides through a reaction with AgOTf/Et3N. Intramolecular cyclization of the tertiary allylic amine to the carbodiimide equilibrates with a zwitterionic intermediate
α,γ-Dioxygenated amides via tandem Brook rearrangement/radical oxygenation reactions and their application to syntheses of γ-lactams
作者:Mikhail K Klychnikov、Radek Pohl、Ivana Císařová、Ullrich Jahn
DOI:10.3762/bjoc.17.58
日期:——
N-allylic silylacetamides and TEMPO is reported. The sequence starts with a new tandem nucleophilic substitution/Brook rearrangement/single electron transfer-induced radical oxygenation furnishing orthogonally protected α,γ-dioxygenated N-allylamides with wide scope, mostly good yields, and partly good diastereo- and enantioselectivity for defined combinations of chiral epoxides and chiral amides
吡咯烷酮是各种生物活性化合物中常见的杂环片段。在此,报道了一种基于两步自由基的方法,从环氧化物、 N-烯丙基甲硅烷基乙酰胺和 TEMPO 开始制备带有三到四个立构中心的 γ-内酰胺。该序列以新的串联亲核取代/布鲁克重排/单电子转移诱导的自由基氧化开始,提供正交保护的α,γ-二氧化N-烯丙基酰胺,其范围广,产率大多良好,并且对于确定的组合具有部分良好的非对映和对映选择性手性环氧化物和手性酰胺。这代表了羰基旁边氧化孪晶 C-C/C-O 双官能化的非常罕见的例子。所得二氧化烯丙酰胺随后进行基于持久自由基效应的5-外-三自由基环化反应,以高产率提供作为非对映体混合物的官能化吡咯烷酮。它们通过碱基介导的平衡聚合成 3,4-反式-γ-内酰胺,可以轻松地进一步多样化。开发了两种反应类型的立体化学模型。
Selective Oxytrifluoromethylation of Allylamines with CO<sub>2</sub>
dioxide (CO2) using copper catalysis, thus leading to important CF3‐containing 2‐oxazolidones. It is also the first time CO2, a nontoxic and easily available greenhouse gas, has been used to tune the difunctionalization of alkenes from amino‐ to oxy‐trifluoromethylation. Of particular note, this multicomponent reaction is highly chemo‐, regio‐, and diastereoselectiveunder redox‐neutral and mild reaction