converted with full regioselectivity into the corresponding arylketones by formal hydration of the triple bond under weak acidic conditions, at times and temperatures (≤95 °C) comparable to those used for terminal alkynes. The process catalyzed by Fe2(SO4)3nH2O in glacial acetic acid exhibits good functional group compatibility, including that with bulky triple bond substituents, and can be extended to
在弱酸性条件下,在与终端炔烃相当的时间和温度(≤95°C)下,通过三键的正式水合,烷基芳基炔烃具有完全的区域选择性,从而转化为相应的芳基酮。Fe 2(SO 4)3 n H 2催化的过程冰乙酸中的O具有良好的官能团相容性,包括具有庞大的三键取代基的官能团相容性,并且可以通过去甲硅烷基化水合序列扩展为芳基三甲基甲硅烷基乙炔一锅转化为乙酰基衍生物的过程。总体反应模式以及质子亲和力数据表明,三键是通过质子转移而不是通过与金属离子的π相互作用激活的。该机理特征与贵金属催化剂的机理不同,解释了Fe 2(SO 4)3 n H 2 O / AcOH催化体系表现出的总区域选择性和对空间位阻的不敏感性。
Improvement in Aqueous Solubility of Retinoic Acid Receptor (RAR) Agonists by Bending the Molecular Structure
pharmaceutical compounds by disrupting intermolecular interactions. Here, we show that introducing a bend into the molecular structure of retinoic acid receptor (RAR) agonists by changing the substitution pattern from para to meta or ortho dramatically enhances aqueous solubility by up to 890‐fold. We found that meta analogs exhibit similar hydrophobicity to the parent para compound, and have lower melting points
compounds. Asymmetricsynthesis of di-, tri-, and tetrasubstituted bioactive molecules has also been achieved. Systematic mechanistic studies and theoretical calculations have revealed the origin of the regioselectivity, the key hydrogenation transition state models, and the sequence of the double and triple hydrogenation processes. The work provides a new choice for the catalyticasymmetricsynthesis of cyclobutanes