910219-78-2Relevant articles and documents
Cu-Photoredox-catalyzed C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes
Zhang, Dayong,Zhang, Yajing
supporting information, p. 4479 - 4483 (2020/10/20)
Visible-light-induced C(sp)-C(sp3) coupling of redox-active esters with terminal alkynes has been developed. The activation of carboxylic acids as their redox-active ester derivatives was important for this decarboxylative alkynylation. The strategy established here facilitates the straightforward introduction of triple-bonded functional groups and avoids additional photocatalysts. A wide range of primary, secondary and tertiary acids can be converted into the target products; so this reaction exhibits a broad substrate scope and tolerance of functional groups. Mechanistic experiments suggested that this reaction may undergo a radical process. Under mild reaction conditions, a copper acetylide ligand as a photocatalyst delivered an electron to redox-active ester derivatives, and generated alkyl radicals. The radicals reacted with Cu(ii) to deliver a Cu(iii) complex, and then reductive elimination gave the products.
Cleavage of C–C and C–O Bonds to Form C–C Bonds: Direct Cross-Coupling between Acetylenic Alcohols and Benzylic Carbonates
Mi, Zhiyuan,Tang, Jiahao,Guan, Zhipeng,Shi, Wei,Chen, Hao
, p. 4479 - 4482 (2018/09/10)
A palladium-catalyzed cross-coupling reaction between C(sp) and C(sp3) centers was achieved in excellent yields via C–C bond cleavage and C–O bond cleavage. This procedure uses relatively stable acetylenic alcohols as reactants instead of unsta
Decarboxylative benzylations of alkynes and ketones
Torregrosa, Robert R. P.,Ariyarathna, Yamuna,Chattopadhyay, Kalicharan,Tunge, Jon A.
supporting information; experimental part, p. 9280 - 9282 (2010/10/20)
Benzyl esters of propiolic and β-keto acids undergo catalytic decarboxylative coupling when treated with appropriate palladium catalysts. Such decarboxylative couplings allow the benzylation of alkynes without the use of strong bases and/or organometallics. This allows the synthesis of sensitive benzylic alkynes that are prone to undergo isomerizations under basic conditions. Additionally, decarboxylation facilitates the site-specific benzylation of diketones and ketoesters under mild, base-free conditions. Ultimately, the methodology described expands our ability to cross-couple medicinally relevant heterocycles.
