1823-52-5Relevant academic research and scientific papers
Synthesis of β-lactones: A highly active and selective catalyst for epoxide carbonylation
Getzler, Yutan D. Y. L.,Mahadevan, Viswanath,Lobkovsky, Emil B.,Coates, Geoffrey W.
, p. 1174 - 1175 (2002)
A new highly active and selective catalyst for the synthesis of β-lactones from CO and epoxides is reported. The catalyst, [(N,N′-bis(3,5-di-tert-butylsalicylidene) phenylenediamino)Al(THF)2][Co(CO)4] ([(salph)Al(THF)2][Co(CO)4]) is easily prepared from the corresponding (salph)AlCl and NaCo(CO)4. At 50 °C and 880 psi of CO, the catalyst (1 mol %) carbonylates epoxides such as propylene oxide, 1-butene oxide, epichlorohydrin, and isobutylene oxide to the lactones β-butyrolactone, β-valerolactone, γ-chloro-β-butyrolactone, and β-methyl-β-butyrolactone in high yield. (R)-Propylene oxide was carbonylated to (R)-β-butyrolactone with retention of stereochemistry. Copyright
Catalyst-controlled regioselective carbonylation of isobutylene oxide to pivalolactone
Hubbell, Aran K.,Lamb, Jessica R.,Klimovica, Kristine,Mulzer, Michael,Shaffer, Timothy D.,MacMillan, Samantha N.,Coates, Geoffrey W.
, p. 12537 - 12543 (2020)
Poly(pivalolactone) (PPVL) is a crystalline polyester with attractive physical and mechanical properties; however, prohibitively expensive syntheses of pivalolactone have thwarted efforts to produce PPVL on an industrial scale. Therefore, we developed a class of highly regioselective sandwich-type catalysts for the carbonylation of isobutylene oxide. These sterically encumbered complexes install carbon monoxide at the substituted epoxide carbon, generating a high level of contrasteric selectivity (up to >99:1). Further catalyst development improved catalyst solubility and reproducibility while maintaining high regioselectivity. In addition, a dibasic ester solvent extended catalyst lifetimes and suppressed side product formation. This contrasteric carbonylation of isobutylene oxide offers a route to sought-after pivalolactone and, therefore, PPVL.
[Lewis acid]+[Co(CO)4]- complexes: A versatile class of catalysts for carbonylative ring expansion of epoxides and aziridines
Mahadevan, Viswanath,Getzler, Yutan D. Y. L.,Coates, Geoffrey W.
, p. 2781 - 2784 (2002)
Efficient carbonyl insertion into C-O and C-N bonds using [Lewis acid]+[Co(CO)4]- complexes 1 and 2 gives regio- and stereoselective carbonylation of a variety of epoxides and aziridines to yield β-lactones and β-lactams, respectively. Both transformations are proposed to occur by the same mechanism, yielding products with inversion of configuration at the site of CO insertion.
SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES FOR THE PRODUCTION OF ALPHA,ALPHA-DISUBSTITUTED BETA-LACTONES
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Paragraph 0077; 0082; 0121-0123, (2021/01/29)
Provided are methods of producing carbonyl compounds (e.g., carbonyl containing compounds) and catalysts for producing carbonyl compounds. Also provided are methods of making polymers from carbonyl compounds and polymers formed from carbonyl compounds. A method may produce carbonyl compounds, such as, for example α,α-disubstituted carbonyl compounds (e.g., α,α-disubstituted β-lactones). The polymers may be produced from α,α-disubstituted β-lactones, which may be produced by a method described herein.
SYSTEMS AND METHODS FOR REGIOSELECTIVE CARBONYLATION OF 2,2-DISUBSTITUTED EPOXIDES
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Paragraph 0085, (2020/06/05)
Provided are methods of carbonylating cyclic substrates to produce carbonyl ated cyclic products. The cyclic substrates may be 2, 2-di substituted epoxides and the cyclic products may be β,β-di substituted lactones. The method may be carried out by forming and pressurizing a reaction mixture of the cyclic substrate, a solvent, carbon monoxide, and a [LA+][CO(CO)4-] catalyst, where [LA+] is a Lewis acid capable of coordinating to the cyclic substrate. The method may proceed with a regioselectivity of 90:10 or greater. The resulting carbonylated cyclic products may be converted to ketone aldol products that retain the stereochemistry and enantiomeric ratio of the carbonyl ated cyclic products.
Regioselective Carbonylation of 2,2-Disubstituted Epoxides: An Alternative Route to Ketone-Based Aldol Products
Hubbell, Aran K.,Lapointe, Anne M.,Lamb, Jessica R.,Coates, Geoffrey W.
supporting information, p. 2474 - 2480 (2019/02/14)
We report the regioselective carbonylation of 2,2-disubstituted epoxides to β,β-disubstituted β-lactones. Mechanistic studies revealed epoxide ring-opening as the turnover limiting step, an insight that facilitated the development of improved reaction conditions using weakly donating, ethereal solvents. A wide range of epoxides can be carbonylated to β-lactones, which are subsequently ring-opened to produce ketone-based aldol adducts, providing an alternative to the Mukaiyama aldol reaction. Enantiopure epoxides were demonstrated to undergo the carbonylation/ring-opening process with retention of stereochemistry to form enantiopure β-hydroxy esters.
Rediscovering copper-based catalysts for intramolecular carbon-hydrogen bond functionalization by carbene insertion
Martin, Carmen,Belderrain, Tomas R.,Perez, Pedro J.
supporting information; scheme or table, p. 4777 - 4781 (2009/12/08)
A series of TpxCu complexes (Tpx = hydrotrispyrazolylborate ligand) have been tested as catalysts for the decomposition of several diazoacetates and N,N-disubstituted diazoacetamides and the subsequent formation of lactones and lacta
