从β-基酸中产生TBAT催化二氧化氨酸的形成.
1Department of Chemistry, Western Washington University, Bellingham, WA 98225 (USA).
Tetrahedron
|January 13, 2025
概括
催化剂可以通过乙烯化和水化来减少β-基. 使用四甲二三四酸盐 (TBAT) 产生周期性二氧化氨酸,可以转化为受保护的1,3-二醇.
科学领域:
- 有机化学 有机化学
- 催化剂是一种催化剂.
- 合成方法论 合成方法论
背景情况:
- β-基是多功能合成中间体.
- 有效的减少和功能化方法对于复杂分子合成至关重要.
研究的目的:
- 开发一种新的合成途径,用于降低和功能化β-基.
- 探索四甲二三酸盐 (TBAT) 在变化中的实用性.
主要方法:
- 催化西乙化,然后进行分子内水化.
- 使用四甲基二三酸盐 (TBAT) 进行直接转换.
- 用有机试剂进行净化和区域选择性环开放的柱状染色学.
主要成果:
- 使用催化和四甲基化物 (TBAF) 的两步序列有效降低了β-基.
- 切换到TBAT允许从β-基子直接形成循环二氧化氨酸.
- 二氧化氨酸被区域选择性地打开,以产生具有选择性二次酒精保护的差异化1,3-二醇.
结论:
- TBAT促进了β-基的新型转化为周期性二氧化氨酸.
- 这种方法可以获得选择性保护的1,3-二醇.
- 一个涉及TBAT催化乙烯形成和分子内碳基化的拟议机制得到了 diastereoselectivity 数据的支持.
相关概念视频
Oxidation of Alkenes: Syn Dihydroxylation with Osmium Tetraoxide
9.8K
Alkenes are converted to 1,2-diols or glycols through a process called dihydroxylation. It involves the addition of two hydroxyl groups across the double bond with two different stereochemical approaches, namely anti and syn. Dihydroxylation using osmium tetroxide progresses with syn stereochemistry.
9.8K
Oxidation of Alkenes: Anti Dihydroxylation with Peroxy Acids
5.6K
Diols are compounds with two hydroxyl groups. In addition to syn dihydroxylation, diols can also be synthesized through the process of anti dihydroxylation. The process involves treating an alkene with a peroxycarboxylic acid to form an epoxide. Epoxides are highly strained three-membered rings with oxygen and two carbons occupying the corners of an equilateral triangle. This step is followed by ring-opening of the epoxide in the presence of an aqueous acid to give a trans diol.
5.6K
Hydroboration-Oxidation of Alkenes
7.8K
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
7.8K
Preparation of Diols and Pinacol Rearrangement
3.3K
Compounds bearing two hydroxyl groups are known as diols. When the hydroxyl groups are located on adjacent carbon atoms, the diols are called vicinal diols or glycols. Under acidic conditions, vicinal diols undergo a specific reaction called pinacol rearrangement.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
The reaction begins with transferring a proton from the acid catalyst to one of the hydroxyl groups, producing an oxonium ion.
3.3K
Alkynes to Aldehydes and Ketones: Hydroboration-Oxidation
17.8K
Introduction
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
One of the convenient methods for the preparation of aldehydes and ketones is via hydration of alkynes. Hydroboration-oxidation of alkynes is an indirect hydration reaction in which an alkyne is treated with borane followed by oxidation with alkaline peroxide to form an enol that rapidly converts into an aldehyde or a ketone. Terminal alkynes form aldehydes, whereas internal alkynes give ketones as the final product.
17.8K
Preparation of Epoxides
7.4K
Overview
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
Epoxides result from alkene oxidation, which can be achieved by a) air, b) peroxy acids, c) hypochlorous acids, and d) halohydrin cyclization.
Epoxidation with Peroxy Acids
Epoxidation of alkenes via oxidation with peroxy acids involves the conversion of a carbon–carbon double bond to an epoxide using the oxidizing agent meta-chloroperoxybenzoic acid, commonly known as MCPBA. Since the O–O bond of peroxy acids is very weak, the addition of electrophilic oxygen of...
7.4K


