170661-44-6Relevant articles and documents
Nickel/Cobalt-Catalyzed C(sp3)-C(sp3) Cross-Coupling of Alkyl Halides with Alkyl Tosylates
Komeyama, Kimihiro,Michiyuki, Takuya,Osaka, Itaru
, p. 9285 - 9291 (2019/10/11)
The C(sp3)-C(sp3) cross-coupling of alkyl halides with alkyl tosylates has been developed by employing a combination of nickel and nucleophilic cobalt catalysts in the presence of a manganese reductant. This method provides a straightforward route to a diverse set of not only secondary-primary but also primary-primary C(sp3)-C(sp3) linkages under mild conditions without using alkyl-metallic reagents. Mechanistic studies suggest the formation of alkyl radicals from both alkyl halides and alkyl tosylates. Additionally, cross-coupling could be applied to the short-step synthesis of a histone deacetylase inhibitor, Vorinostat.
Nickel-Catalyzed Cross-Coupling of Umpolung Carbonyls and Alkyl Halides
Zhu, Dianhu,Lv, Leiyang,Qiu, Zihang,Li, Chao-Jun
, p. 6312 - 6322 (2019/05/24)
An effective nickel-catalyzed cross-coupling of Umpolung carbonyls and alkyl halides was developed. Complementary to classical alkylation techniques, this reaction utilizes Umpolung carbonyls as the environmentally benign alkyl nucleophiles, providing an efficient and selective catalytic alternative to the traditional use of highly reactive alkyl organometallic reagents.
Metallaphotoredox-catalysed sp3-sp3 cross-coupling of carboxylic acids with alkyl halides
Johnston, Craig P.,Smith, Russell T.,Allmendinger, Simon,MacMillan, David W. C.
, p. 322 - 325 (2016/08/30)
In the past 50 years, cross-coupling reactions mediated by transition metals have changed the way in which complex organic molecules are synthesized. The predictable and chemoselective nature of these transformations has led to their widespread adoption across many areas of chemical research. However, the construction of a bond between two sp3-hybridized carbon atoms, a fundamental unit of organic chemistry, remains an important yet elusive objective for engineering cross-coupling reactions. In comparison to related procedures with sp2-hybridized species, the development of methods for sp3-sp3 bond formation via transition metal catalysis has been hampered historically by deleterious side-reactions, such as β-hydride elimination with palladium catalysis or the reluctance of alkyl halides to undergo oxidative addition. To address this issue, nickel-catalysed cross-coupling processes can be used to form sp3-sp3 bonds that utilize organometallic nucleophiles and alkyl electrophiles. In particular, the coupling of alkyl halides with pre-generated organozinc, Grignard and organoborane species has been used to furnish diverse molecular structures. However, the manipulations required to produce these activated structures is inefficient, leading to poor step-and atom-economies. Moreover, the operational difficulties associated with making and using these reactive coupling partners, and preserving them through a synthetic sequence, has hindered their widespread adoption. A generically useful sp3-sp3 coupling technology that uses bench-stable, native organic functional groups, without the need for pre-functionalization or substrate derivatization, would therefore be valuable. Here we demonstrate that the synergistic merger of photoredox and nickel catalysis enables the direct formation of sp3-sp3 bonds using only simple carboxylic acids and alkyl halides as the nucleophilic and electrophilic coupling partners, respectively. This metallaphotoredox protocol is suitable for many primary and secondary carboxylic acids. The merit of this coupling strategy is illustrated by the synthesis of the pharmaceutical tirofiban in four steps from commercially available starting materials.
