Selective deprotection of silyl-protected phenols using solid NaOH and a phase transfer catalyst
摘要:
Aryl silyl ethers can be deprotected to yield phenols in good to excellent yields using a biphasic system of 10 equivalents of NaOH and catalytic Bu4NHSO4 in 1,4-dioxane. Alkyl silyl ethers prepared using a variety of silyl protecting groups survive under these conditions, allowing selective deprotection of silyl-protected phenols in the presence of silyl-protected alcohols. (C) 1999 Elsevier Science Ltd. All rights reserved.
酚类的氧化是广泛研究的主题,但很少有具有化学和区域选择性的催化需氧实例。在这里,我们描述了在铜 (Cu) 催化的有氧条件下苯酚的正氧化或氧化偶联的条件,这些条件会产生邻醌、双酚或苯并氧杂环庚烷。We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. 此外,我们评估了取代基对苯酚的影响,并证明了它们对原氧化和氧化偶联途径之间选择性的影响。
An efficient method for the dehydrogenative coupling of silanes with alcohols under photocatalysis was developed. The reaction proceeded in the presence of Ru(bpy)3Cl2 (0.5 mol%) under visible light irradiation in acetonitrile at room temperature. The developed methodology was also applicable for the synthesis of silanols using water as a coupling partner.
Reductive Etherification of Aldehydes and Ketones with Alcohols and Triethylsilane Catalysed by Yb(OTf)
<sub>3</sub>
: an Efficient One‐Pot Benzylation of Alcohols
The one‐pot synthesis of symmetrical and unsymmetrical ethers from aldehydes and ketones can be conveniently performed using Yb(OTf)3 as catalyst and triethylsilane as reducing agent in presence of alcohols. This methodology leads to the synthesis of ether derivatives with good yields. Notably, this process resulted a useful tool to protect alcohols as benzyl ether derivatives using differently substituted
compounds featuring nitrogen atoms are typically regarded as Lewis bases and are extensively employed as donor ligands in coordination chemistry or as nucleophiles in organic chemistry. By contrast, electrophilic nitrogen-containing compounds are much rarer. Nitrenium cations are a new family of nitrogen-based Lewis acids, the reactivity of which remains largely unexplored. In this work, nitrenium
LiOAc-Catalyzed Chemoselective Deprotection of Aryl Silyl Ethers under Mild Conditions
作者:Bing Wang、Hui-Xia Sun、Zhi-Hua Sun
DOI:10.1021/jo802472s
日期:2009.2.20
An efficient and chemoselective deprotection protocol for aryl silyl ethers using LiOAc as a bifunctional Lewis acid-Lewis base catalyst was described. Acetates, epoxides, and aliphatic silyl ethers were preserved, whereas aryl TBS and TBDPS ethers can be differentiated.
Akerman, Acta Chemica Scandinavica (1947), 1957, vol. 11, p. 373,375