52121-67-2Relevant articles and documents
CuBr2-catalyzed ring opening/formylation reaction of cyclopropyl carbinols with DMF to synthesize formate esters
Zhuang, Daijiao,Gatera, Tharcisse,Yan, Rulong
supporting information, (2020/10/19)
An unprecedented protocol for the synthesis of formate esters has been developed by employing N,N-dimethylformamide (DMF) as both the source of CHO and solvent. This reaction undergoes ring opening of the cyclopropyl carbinols and in situ formation of homoallylic alcohols, which reacts with DMF to give the desired products. The substrate cyclopropyl carbinols with different groups participate smoothly in this process and the desired products are obtained in moderate to good yields.
C-Alkylation of Secondary Alcohols by Primary Alcohols through Manganese-Catalyzed Double Hydrogen Autotransfer
El-Sepelgy, Osama,Matador, Esteban,Brzozowska, Aleksandra,Rueping, Magnus
, p. 3099 - 3102 (2018/09/27)
A new Mn-catalyzed alkylation of secondary alcohols with non-activated alcohols is presented. The use of a stable and well-defined manganese pincer complex, stabilized by a PNN ligand, together with a catalytic amount of base enabled the conversion of renewable alcohol feedstocks to a broad range of higher-value alcohols in good yields with water as the sole byproduct. The strategy eliminates the need for exogenous and detrimental alkyl halides as well as the use of noble metal catalysts, making the C-alkylation through double hydrogen autotransfer a highly sustainable and environmentally benign process. Mechanistic investigations support a hydrogen autotransfer mechanism in which a non-innocent ligand plays a crucial role.
Tandem Cross Coupling Reaction of Alcohols for Sustainable Synthesis of β-Alkylated Secondary Alcohols and Flavan Derivatives
Shee, Sujan,Paul, Bhaskar,Panja, Dibyajyoti,Roy, Bivas Chandra,Chakrabarti, Kaushik,Ganguli, Kasturi,Das, Ayan,Das, Gourab Kanti,Kundu, Sabuj
supporting information, p. 3888 - 3893 (2017/10/07)
A Ru(II) NHC complex (loading down to 0.001 mol%) catalyzed cross coupling of a broad range of aromatic, aliphatic and heterocyclic alcohols is reported. This protocol also functioned efficiently under solvent-free conditions. Remarkably, this catalytic system disclosed so far the highest TON of 288000 for the cross coupling of alcohols. Notably, this methodology was successfully applied for the one-pot synthesis of a range of flavan derivatives. A detailed DFT studies and kinetic experiments were performed to understand the reaction mechanism as well as the high reactivity of this catalytic system. (Figure presented.).
Cobalt-Catalyzed Alkylation of Secondary Alcohols with Primary Alcohols via Borrowing Hydrogen/Hydrogen Autotransfer
Freitag, Frederik,Irrgang, Torsten,Kempe, Rhett
supporting information, p. 12110 - 12113 (2017/09/14)
Alcohols are promising sustainable starting materials because they can be obtained from abundant and indigestible biomass. The substitution of expensive noble metals in catalysis by earth abundant 3d metals, such as Mn, Fe, or Co, (nonprecious or base metals) is a related key concept with respect to sustainability. Here, we report on the first cobalt-catalyzed alkylation of secondary alcohols with primary alcohols. Easy-to-synthesize and easy-to-activate PN5P-pincer-ligand-stabilized Co complexes developed in our laboratory mediate the reaction most efficiently. The catalysis is applicable to a broad substrate scope and proceeds under relatively mild conditions. We have even demonstrated the coupling of a variety of purely aliphatic alcohols with a base or nonprecious metal catalyst. Mechanistic studies indicate that the reaction follows the borrowing hydrogen or hydrogen autotransfer concept.
Bifunctional Ru(II) complex catalysed carbon-carbon bond formation: an eco-friendly hydrogen borrowing strategy
Chakrabarti, Kaushik,Paul, Bhaskar,Maji, Milan,Roy, Bivas Chandra,Shee, Sujan,Kundu, Sabuj
, p. 10988 - 10997 (2016/12/06)
The atom economical borrowing hydrogen methodology enables the use of alcohols as alkylating agents for selective C-C bond formation. A bifunctional 2-(2-pyridyl-2-ol)-1,10-phenanthroline (phenpy-OH) based Ru(ii) complex (2) was found to be a highly efficient catalyst for the one-pot β-alkylation of secondary alcohols with primary alcohols and double alkylation of cyclopentanol with different primary alcohols. Exploiting the metal-ligand cooperativity in complex 2, several aromatic, aliphatic and heteroatom substituted alcohols were selectively cross-coupled in high yields using significantly low catalyst loading (0.1 mol%). An outer-sphere mechanism is proposed for this system as exogenous PPh3 has no significant effect on the rate of the reaction. Notably, this is a rare one-pot strategy for β-alkylation of secondary alcohols using a bifunctional Ru(ii)-complex. Moreover, this atom-economical methodology displayed the highest cumulative turn over frequency (TOF) among all the reported transition metal complexes in cross coupling of alcohols.
Bifunctional RuII-Complex-Catalysed Tandem C?C Bond Formation: Efficient and Atom Economical Strategy for the Utilisation of Alcohols as Alkylating Agents
Roy, Bivas Chandra,Chakrabarti, Kaushik,Shee, Sujan,Paul, Subhadeep,Kundu, Sabuj
supporting information, p. 18147 - 18155 (2016/12/16)
Catalytic activities of a series of functional bipyridine-based RuIIcomplexes in β-alkylation of secondary alcohols using primary alcohols were investigated. Bifunctional RuIIcomplex (3 a) bearing 6,6’-dihydroxy-2,2’-bipyridine (6DHBP) ligand exhibited the highest catalytic activity for this reaction. Using significantly lower catalyst loading (0.1 mol %) dehydrogenative carbon?carbon bond formation between numerous aromatic, aliphatic and heteroatom substituted alcohols were achieved with high selectivity. Notably, for the synthesis of β-alkylated secondary alcohols this protocol is a rare one-pot strategy using a metal–ligand cooperative RuIIsystem. Remarkably, complex 3 a demonstrated the highest reactivity compared to all the reported transition metal complexes in this reaction.
Strategic Application and Transformation of ortho-Disubstituted Phenyl and Cyclopropyl Ketones to Expand the Scope of Hydrogen Borrowing Catalysis
Frost, James R.,Cheong, Choon Boon,Akhtar, Wasim M.,Caputo, Dimitri F. J.,Stevenson, Neil G.,Donohoe, Timothy J.
supporting information, p. 15664 - 15667 (2016/01/09)
The application of an iridium-catalyzed hydrogen borrowing process to enable the formation of α-branched ketones with higher alcohols is described. In order to facilitate this reaction, ortho-disubstituted phenyl and cyclopropyl ketones were recognized as crucial structural motifs for C-C bond formation. Having optimized the key catalysis step, the ortho-disubstituted phenyl products could be further manipulated by a retro-Friedel-Crafts acylation reaction to produce synthetically useful carboxylic acid derivatives. In contrast, the cyclopropyl ketones underwent homoconjugate addition with several nucleophiles to provide further functionalized branched ketone products.
Use of alkyl 2,4,6-triisopropylbenzoates in the asymmetric homologation of challenging boronic esters
Larouche-Gauthier, Robin,Fletcher, Catherine J.,Couto, Irantzu,Aggarwal, Varinder K.
supporting information; experimental part, p. 12592 - 12594 (2012/01/05)
(-)-Sparteine induced lithiation of primary 2,4,6-triisopropylbenzoates and subsequent homologation of boronic esters is reported. A comparative study with lithiated N,N-diisopropylcarbamates has demonstrated the superiority of the hindered benzoate. The Royal Society of Chemistry 2011.
A catalytic and enantioselective cyclopropylation of aldehydes using dicyclopropylzinc
Shibata, Takanori,Tabira, Hayami,Soai, Kenso
, p. 177 - 178 (2007/10/03)
Enantioselective cyclopropylation of various aldehydes proceeds using dicyclopropylzinc in the presence of a catalytic amount of chiral amino alcohol or thiophosphoramidate with Ti(OPr1)4 to provide enantiomerically enriched cyclopropyl alkanols (up to 96.6% ee).
Hydrozirconation of alkenyloxirane derivatives: Preparation of cycloalkylmethanols
Harada, Susumu,Kowase, Noboru,Tabuchi, Nobuhito,Taguchi, Takeo,Dobashi, Yasuo,Dobashi, Akira,Hanzawa, Yuji
, p. 753 - 766 (2007/10/03)
Cyclopentyl and cyclopropylmethanol derivatives were efficiently prepared through a chemoselective hydrozirconation reaction of (1- butenyl)oxirane and vinyloxirane with Cp2ZrHCl. However, the attemped reaction of (1-pentenyl)oxirane or (1-propenyl)oxirane failed to yield cyclohexyl or cyclobutylmethanols. The ring formation was stereospecific and proceeded with the inversion of the configuration at the reacting oxirane carbon. The origin of stereospecificity and the stereoselectivity in the formation of cyclopropylmethanols was presumed by the approach of the Schwartz reagent from the less hindered site of the stable gauche-conformer of the vinyloxirane compound in the transition state. (Cyclopropylmethyl)amine derivatives were also prepared by the treatment of vinylaziridine derivatives with Cp2ZrHCl.
