99334-84-6Relevant articles and documents
Site-Selective Alkoxylation of Benzylic C?H Bonds by Photoredox Catalysis
Lee, Byung Joo,DeGlopper, Kimberly S.,Yoon, Tehshik P.
supporting information, p. 197 - 202 (2019/11/26)
Methods that enable the direct C?H alkoxylation of complex organic molecules are significantly underdeveloped, particularly in comparison to analogous strategies for C?N and C?C bond formation. In particular, almost all methods for the incorporation of alcohols by C?H oxidation require the use of the alcohol component as a solvent or co-solvent. This condition limits the practical scope of these reactions to simple, inexpensive alcohols. Reported here is a photocatalytic protocol for the functionalization of benzylic C?H bonds with a wide range of oxygen nucleophiles. This strategy merges the photoredox activation of arenes with copper(II)-mediated oxidation of the resulting benzylic radicals, which enables the introduction of benzylic C?O bonds with high site selectivity, chemoselectivity, and functional-group tolerance using only two equivalents of the alcohol coupling partner. This method enables the late-stage introduction of complex alkoxy groups into bioactive molecules, providing a practical new tool with potential applications in synthesis and medicinal chemistry.
Indium(i)-catalyzed alkyl-allyl coupling between ethers and an allylborane
Dao, Hai Thanh,Schneider, Uwe,Kobayashi, Shu
supporting information; experimental part, p. 692 - 694 (2011/03/22)
An efficient method for alkyl-allyl cross-coupling between ethers and a 9-BBN-derived allylborane catalyzed by indium(i) triflate has been developed. The allylborane proved to be essential to obtain the desired products in high yields. The reaction displayed good substrate scope including high functional group tolerance. The Royal Society of Chemistry 2011.
Absolute reactivity of the 4-methoxycumyl cation in non-acid zeolites
O'Neill, Melanie A.,Cozens, Frances L.,Schepp, Norman P.
, p. 6017 - 6027 (2007/10/03)
The reactivity of the 4-methoxycumyl cation in a series of alkali metal cation-exchanged zeolites (LiY, NaY, KY, RbY CsY, NaX, NaMor, and Naβ) in the absence and presence of coadsorbed alcohols and water is examined using nanosecond laser flash photolysis. In dry zeolites, the absolute reactivity of the carbocation is found to be strongly dependent on the nature of the alkali counterion, the Si/Al ratio, and the framework morphology, with the lifetime of the carbocation in Naβ being almost 10000-fold longer than in CsY. The results suggest a mechanism for carbocation decay involving direct participation of the zeolite framework as a nucleophile, leading to the generation of a framework-bound alkoxy species. Intrazeolite addition reactions of alcohols and water to the 4-methoxycumyl cation can be described in terms of both dynamic and static quenching involving molecular diffusion through the heterogeneous topology and rapid coupling between the alcohol and the carbocation encapsulated within the same cavity. The dynamics of the quenching reactions are different from similar reactions in homogeneous solution due to both the passive and active influences of the zeolite environment. In a passive sense, the zeolite decreases the reactivity of the nucleophilic quencher by hindering molecular diffusion. However, the zeolite actively promotes the efficiency of intracavity coupling by enhancing the deprotonation of the oxonium ion intermediate, allowing the reaction to go to completion.
