Efficient Rhodium-Catalyzed Asymmetric Hydrogenation for the Synthesis of a New Class of N-Aryl β-Amino Acid Derivatives
摘要:
N-Aryl beta-amino esters were obtained by asymmetric hydrogenation of a new class of N-aryl beta-enamino esters. High conversions and up to 96.3% ee values were achieved with a Rh-TangPhos catalyst.
Efficient Synthetic Method for β-Enamino Esters Catalyzed by Yb(OTf)3 under Solvent-Free Conditions
作者:Ravi Varala、Sreelatha Nuvula、Srinivas R. Adapa
DOI:10.1071/ch06239
日期:——
esters have been synthesized in moderate to excellent yields by reacting 1,3-dicarbonyl compounds with amines in the presence of catalytic amounts of Yb(OTf)3 (2 mol%). The reaction proceeds smoothly at ambient temperature undersolvent-freeconditions. The catalyst can be recovered and reused.
Direct Trifluoromethylthiolation and Perfluoroalkylthiolation of C(sp
<sup>2</sup>
)H Bonds with CF
<sub>3</sub>
SO
<sub>2</sub>
Na and R
<sub>f</sub>
SO
<sub>2</sub>
Na
A new method for CF3SO2Na‐based direct trifluoromethylthiolation of C(sp2)H bonds has been developed. CF3SSCF3 is generated in situ from cheap and easy‐to‐handle CF3SO2Na, and in the presence of CuCl can be used for electrophilic trifluoromethylthiolation of indoles, pyrroles, and enamines. The method has been extended to perfluoroalkylthiolation reactions using RfSO2Na.
已开发出一种基于CF 3 SO 2 Na的C(sp 2)H键直接三氟甲基硫醇化的新方法。CF 3 SSCF 3是由便宜且易于处理的CF 3 SO 2 Na原位生成的,在存在CuCl的情况下,可用于吲哚,吡咯和烯胺的亲电三氟甲基硫醇化反应。该方法已扩展到使用R f SO 2 Na的全氟烷基硫醇化反应。
Cu(II)-Catalyzed Enantioselective Conjugate Reduction for the Synthesis of<i>N</i>-Aryl<i>β</i>-Amino Acid Esters
A new set of reaction conditions has been established and allowed for the first non‐noble Cu(II)‐catalyzed asymmetric 1,4‐hydrosilylation of N‐aryl β‐enamino esters under air to afford a selection of N‐aryl β‐amino acid esters of moderate‐to‐good enantiopurities (ee up to 91%).
Direct C-Arylation of β-Enamino Esters and Ketones with Arynes
作者:Yeeman K. Ramtohul、Anik Chartrand
DOI:10.1021/ol063057k
日期:2007.3.1
An efficient, mild, and general method for the C-arylation beta-enamino esters and ketones with arynes has been developed. This methodology provides a facile and direct access to a variety of substituted aromatic beta-enamino compounds in moderate to excellent yield.
Efficient Rhodium-Catalyzed Asymmetric Hydrogenation for the Synthesis of a New Class of <i>N</i>-Aryl β-Amino Acid Derivatives
作者:Qian Dai、Weiran Yang、Xumu Zhang
DOI:10.1021/ol0523897
日期:2005.11.1
N-Aryl beta-amino esters were obtained by asymmetric hydrogenation of a new class of N-aryl beta-enamino esters. High conversions and up to 96.3% ee values were achieved with a Rh-TangPhos catalyst.