Phase-transfer-catalysed asymmetric synthesis of tetrasubstituted allenes
作者:Takuya Hashimoto、Kazuki Sakata、Fumiko Tamakuni、Mark J. Dutton、Keiji Maruoka
DOI:10.1038/nchem.1567
日期:2013.3
Allenes are molecules based on three carbons connected by two cumulated carbon–carbon double bonds. Given their axially chiral nature and unique reactivity, substituted allenes have a variety of applications in organic chemistry as key synthetic intermediates and directly as part of biologically active compounds. Although the demands for these motivated many endeavours to make axially chiral, substituted
Rhodium(III)-Catalyzed Diastereoselective Synthesis of 1-Aminoindanes via C−H Activation
作者:Sang Hoon Han、Neeraj Kumar Mishra、Mijin Jeon、Saegun Kim、Hyung Sik Kim、Seung-Young Jung、Young Hoon Jung、Jin-Mo Ku、In Su Kim
DOI:10.1002/adsc.201701082
日期:2017.11.23
nitroalkenes is described. This transformation efficiently leads to the diastereoselective synthesis of pharmacologically privileged 1‐aminoindane derivatives via the C−H alkylation followed by subsequent intramolecularcyclization. Notably, single diastereomers in all cases were observed, and the relative stereochemistry of products was confirmed by the X‐ray crystallographic data.
Complementary chemistry! α‐Isocupreine (α‐ICPN) was synthesized for the first time in one step fromquinine by treatment with CF3SO3H (see scheme). This compound serves as an enantiocomplementarycatalyst to β‐isocupreidine (β‐ICD) in the Morita–Baylis–Hillman reaction.
互补化学!通过CF 3 SO 3 H处理,从奎宁一步一步合成了α-异cupreine(α-ICPN)(参见方案)。在Morita-Baylis-Hillman反应中,该化合物可作为β-异cupreidine(β-ICD)的对映体互补催化剂。
Molecular sieve mediated decarboxylative Mannich and aldol reactions of β-ketoacids
作者:Fangrui Zhong、Chunhui Jiang、Weijun Yao、Li-Wen Xu、Yixin Lu
DOI:10.1016/j.tetlet.2013.06.030
日期:2013.8
A molecular sieve mediated decarboxylativeMannichreaction of β-ketoacids with sulfonyl imines is reported; this protocol leads to an efficient preparation of synthetically useful β-amino ketones. An analogous molecular sieve promoted decarboxylative aldol reaction between β-ketoacids and isatins is also described, which affords bioactive 3-substituted-3-hydroxy-oxindoles in excellent yields.
Invertible Enantioselectivity in 6′-Deoxy-6′-acylamino-β-isocupreidine-Catalyzed Asymmetric Aza-Morita−Baylis−Hillman Reaction: Key Role of Achiral Additive
作者:Nacim Abermil、Géraldine Masson、Jieping Zhu
DOI:10.1021/ol901920s
日期:2009.10.15
(1e)-catalyzed aza-Morita−Baylis−Hillmanreaction between N-sulfonylimines 3 and alkyl vinyl ketones 4 produced the (R)-enriched adducts 5. By adding a catalytic amount of β-naphthol (2a), the enantioselectivity of the same reaction was inversed leading to (S)-5 in excellent yields and enantioselectivities. Both aromatic and aliphaticimines are accepted as substrates for this reaction.