15360-00-6Relevant articles and documents
A Noncoordinating Acid-Base Catalyst for the Mild and Nonreversible tert-Butylation of Alcohols and Phenols
Fandrick, Keith R.,Patel, Nitinchandra D.,Radomkit, Suttipol,Chatterjee, Arindom,Braith, Stefan,Fandrick, Daniel R.,Busacca, Carl A.,Senanayake, Chris H.
, p. 4877 - 4882 (2021)
A mild and nonreversible tert-butylation of alcohols and phenols can be achieved in high yields using the noncoordinating acid-base catalyst [bis(trifluoromethane)sulfonimide and 2,6-lutidine] with a tert-butylation reagent, tert-butyl 2,2,2-trichloroacetimidate. This method allows the use of substrates containing acid sensitive groups such as ketal, Boc, and boronate esters.
Zn- And Cu-catalyzed coupling of tertiary alkyl bromides and oxalates to forge challenging C?O, C?S, and C?N bonds
Gong, Yuxin,Zhu, Zhaodong,Qian, Qun,Tong, Weiqi,Gong, Hegui
supporting information, p. 1005 - 1010 (2021/02/01)
We describe here the facile construction of sterically hindered tertiary alkyl ethers and thioethers via the Zn(OTf)2catalyzed coupling of alcohols/phenols with unactivated tertiary alkyl bromides and the Cu(OTf)2-catalyzed thiolation of unactivated tertiary alkyl oxalates with thiols. The present protocol represents one of the most effective unactivated tertiary C(sp3)? heteroatom bond-forming conditions via readily accessible Lewis acid catalysis that is surprisingly less developed.
A study of diketopiperazines as electron-donor initiators in transition metal-free haloarene-arene coupling
Cumine, Florimond,Zhou, Shengze,Tuttle, Tell,Murphy, John A.
, p. 3324 - 3336 (2017/04/21)
Several diketopiperazines have been shown to promote carbon-carbon coupling between benzene and aryl halides in the presence of potassium tert-butoxide and without the assistance of a transition metal catalyst. The structure of the diketopiperazine has an influence on its reductive potential and can help to promote the coupling of the more challenging aryl bromides with benzene.
Iron-mediated direct arylation of unactivated arenes in air
Huang, Yuxing,Moret, Marc-Etienne,Klein Gebbink, Robertus J. M.
supporting information, p. 3788 - 3793 (2014/06/24)
Biaryls are a common motif in both natural and synthetic chemicals. Several methods have recently been reported for the preparation of these compounds using direct arylation catalyzed by iron, other base metals, or transition-metal-free systems. To date, these methods have all required inert and/or forcing conditions, which limited their application in routine organic synthesis. In this article we report a protocol for direct arylation using a convenient FeCl3/1,10-phenanthroline system as precatalyst. The reaction proceeds under mild conditions (100 °C), under air, and with non-distilled solvent. A simple, environmentally benign catalytic system based on iron trichloride and phenanthroline has been developed for the direct arylation of unactivated arenes with aryl halides under air. Copyright
An eco-sustainable erbium(iii)-catalyzed method for formation/cleavage of O-tert-butoxy carbonates
Procopio, Antonio,Cravotto, Giancarlo,Oliverio, Manuela,Costanzo, Paola,Nardi, Monica,Paonessa, Rosina
body text, p. 436 - 443 (2011/04/17)
A new simple and effective method for the formation/cleavage of O-tert-butoxy carbonates of alcohols and phenols is proposed. Mesoporous silica-supported Er(iii) (ErIII-MCM-41) was used as an efficient and reusable solid catalyst in the solvent-free ultrasound-assisted synthesis of Boc-carbonate derivatives of a wide range of alcohols and phenols. The fast, selective deprotection of Boc-derivatives is achieved with a very low amount of Er(OTf)3 in ethanol under microwave irradiation. Therefore, the entire protection/de-protection process is very attractive, from the point of view of sustainability.
An eco-sustainable erbium(III) triflate catalyzed formation and cleavage of tert -butyl ethers
Procopio, Antonio,Costanzo, Paola,Curini, Massimo,Nardi, Monica,Oliverio, Manuela,Paonessa, Rosina
supporting information; experimental part, p. 73 - 78 (2011/03/19)
An eco-compatible method, which permits the formation or cleavage of tert-butyl ethers of alcohols and phenols, is proposed. The protection step is performed in solvent-free conditions at room temperature using catalytic amount of Er(OTf)3. The catalyst is easily- recovered from the aqueous phase and reused several times without significant loss of activity. The deprotection step developed is also highly eco-friendly since the tert-butyl group is removed very quickly from alcohols and phenols in methanol using MW irradiation-. Georg Thieme Verlag Stuttgart · New York.
A convenient synthesis of tert-butyl ethers under microwave condition
Mahammed,Keshava Murthy,Mohana Raju
, p. 575 - 578 (2008/09/20)
Synthesis of tert-butyl ethers from various alcohols and substituted phenols can be achieved using tert-butyl bromide in the presence of basic lead carbonate as a catalyst under microwave irradiation in absence of solvent. The catalyst is easily recovered via filtration and reused up to three times without appreciable loss of activity.
Efficient synthesis of tert-butyl ethers under solvent-free conditions
Rai, Neithnadka Premsai,Arunachalam, Pirama Nayagam
, p. 2891 - 2896 (2008/02/13)
A simple and efficient synthesis of tert-butyl ethers from various alcohols and substituted phenols using tert-butyl bromide in the presence of basic lead carbonate as a catalyst. The catalyst is easily recovered via filtration and can be reused up to three times without appreciable loss of activity. Copyright Taylor & Francis Group, LLC.
Alcohols and di-tert-butyl dicarbonate: How the nature of the Lewis acid catalyst may address the reaction to the synthesis of tert-butyl ethers
Bartoli, Giuseppe,Bosco, Marcella,Carlone, Armando,Dalpozzo, Renato,Locatelli, Manuela,Melchiorre, Paolo,Sambri, Letizia
, p. 9580 - 9588 (2007/10/03)
The reaction between alcohols and Boc2O leads to the formation of ferf-butyl ethers and/or Boc-alcohols, depending on the nature of the Lewis acid catalyst. Product distribution is mainly tuned by the anionic part of the salt. Perchlorates and Inflates, anions with highly delocalized negative charge, give prevalent or exclusive ether formation. On the other hand, Boc alcohols are the main or exclusive products with un-delocalized isopropoxide or low-delocalized acetate ions. The metal ion influences only the reaction rate, roughly following standard parameters for calculating Lewis acidity. A reaction mechanism is supposed, and a series of experimental evidences is reported to support it. These studies allowed us to conclude that, to synthesize tert-butyl ethers, in reactions involving aliphatic alcohols, Mg(ClO4) 2 or Al(ClO4)3 represents the best compromise between costs and efficiency of the reaction, while, in reactions involving phenols, Sc(OTf)3 is the best choice, since aromatic tert-butyl ethers are not stable in the presence of perchlorates.
Unusual and unexpected reactivity of t-butyl dicarbonate (Boc2O) with alcohols in the presence of magnesium perchlorate. A new and general route to t-butyl ethers
Bartoli, Giuseppe,Bosco, Marcella,Locatelli, Manuela,Marcantoni, Enrico,Melchiorre, Paolo,Sambri, Letizia
, p. 427 - 430 (2007/10/03)
(Chemical Equation Presented) A new mild method for protecting alcohols as t-butyl ethers is reported. The reaction proceeds with Mg(ClO4) 2 and Boc2O and shows general applicability. The deprotection of t-butyl ethers has also been revisited. Preliminary results indicate the CeCl3·7H2O/Nal system is a very suitable catalyst for their removal.
