828-45-5Relevant articles and documents
Nickel-catalyzed carbon-carbon bond-forming reactions of unactivated tertiary alkyl halides: Suzuki arylations
Zultanski, Susan L.,Fu, Gregory C.
supporting information, p. 624 - 627 (2013/03/14)
The first Suzuki cross-couplings of unactivated tertiary alkyl electrophiles are described. The method employs a readily accessible catalyst (NiBr2·diglyme/4,4′-di-tert-butyl-2,2′-bipyridine, both commercially available) and represents the initial example of the use of a group 10 catalyst to cross-couple unactivated tertiary electrophiles to form C-C bonds. This approach to the synthesis of all-carbon quaternary carbon centers does not suffer from isomerization of the alkyl group, in contrast with the umpolung strategy for this bond construction (cross-coupling of a tertiary alkylmetal with an aryl electrophile). Preliminary mechanistic studies are consistent with the generation of a radical intermediate along the reaction pathway.
Carbon-based leaving group in substitution reactions: Functionalization of sp3-hybridized quaternary and tertiary benzylic carbon centers
Mahoney, Stuart J.,Lou, Tiantong,Bondarenko, Ganna,Fillion, Eric
supporting information; experimental part, p. 3474 - 3477 (2012/09/05)
Lewis acid promoted substitution reactions employing Meldrum's acid and 5-methyl Meldrum's acid as carbon-based leaving groups are described which transform unstrained quaternary and tertiary benzylic Csp 3-Csp3 bonds into Csp3-X bonds (X = C, H, N). Importantly, this reaction has a broad scope in terms of both suitable substrates and nucleophiles with good to excellent yields obtained (typically >90%).
Selective alkylation of βII-tubulin and thioredoxin-1 by structurally related subsets of aryl chloroethylureas leading to either anti-microtubules or redox modulating agents
Fortin, Jessica S.,Cote, Marie-France,Lacroix, Jacques,Desjardins, Michel,Petitclerc, Eric,C.-Gaudreault, Rene
, p. 7277 - 7290 (2008/12/22)
Aryl chloroethylureas (CEUs) are potent anti-neoplastic agents alkylating specific intracellular proteins such as βII-tubulin. Recently we have identified a new subset of CEU derived from compound 36 that alkylates thioredoxin isoform 1 (Trx-1), inhibits the nuclear translocation of Trx-1, and favors the accumulation of cells in G0/G1 phase. We have evaluated the effects of various substituents and their position on the aromatic ring of a series of derivatives of 36 on (i) the anti-proliferative activity, (ii) the cell cycle progression, (iii) the nuclear translocation of Trx-1, and (iv) their covalent binding to β-tubulin. The same experiments were performed on representative CEU derivatives where the 2-chloroethyl amino moiety is replaced by either an ethyl, a 2-aminooxazolinyl or a 2-chloroacetyl group. On one hand, our results suggest that CEUs substituted on the phenyl ring at position 3 or 4 by cycloalkyl and substituted cycloalkyl or cycloalkoxy groups inhibit the nuclear translocation of Trx-1 and arrest the cell cycle progression in G0/G1. On the other hand, CEUs substituted by a fused aromatic ring, an aliphatic chain, or a fused aliphatic ring are alkylating βII-tubulin but not Trx-1. Beside the expected inactivity of the ethylurea derivatives, none of the modification to the electrophilic moiety led to cross-selectivity of the drugs toward β-tubulin but increased the anti-proliferative activity and resulted in mitigated effects on Trx-1 translocation.
