62939-60-0Relevant academic research and scientific papers
Four-Step One-Pot Catalytic Asymmetric Synthesis of Polysubstituted Tricyclic Compounds: Lipase-Catalyzed Dynamic Kinetic Resolution Followed by an Intramolecular Diels-Alder Reaction
Tsuchimochi, Izuru,Hori, Shuhei,Takeuchi, Yasuo,Egi, Masahiro,Satoh, Tomo-O,Kanomata, Kyohei,Ikawa, Takashi,Akai, Shuji
supporting information, p. 822 - 828 (2021/02/16)
Starting from readily available tertiary alcohols, four different reactions (a 1,3-migration of a hydroxy group, kinetic resolution, racemization, and an intramolecular Diels-Alder reaction) took place under co-catalysis by lipase and oxovanadium compounds in a one-pot process to produce polysubstituted tricyclic carbon frameworks in high yields and with high enantioselectivities. The key to the success of this process was the discovery that a silyl group attached to the terminal carbon of the vinyl moiety completely controls the direction of hydroxy group migration.
Chemo-Enzymatic Oxidative Rearrangement of Tertiary Allylic Alcohols: Synthetic Application and Integration into a Cascade Process
Brenna, Elisabetta,Crotti, Michele,De Pieri, Matteo,Gatti, Francesco G.,Manenti, Gabriele,Monti, Daniela
supporting information, p. 3677 - 3686 (2018/06/04)
A chemo-enzymatic catalytic system, comprised of Bobbitt's salt and laccase from Trametes versicolor, allowed the [1,3]-oxidative rearrangement of endocyclic allylic tertiary alcohols into the corresponding enones under an Oxygen atmosphere in aqueous media. The yields were in most cases quantitative, especially for the cyclopent-2-en-1-ol or the cyclohex-2-en-1-ol substrates without an electron withdrawing group (EWG) on the side chain. Transpositions of macrocyclic alkenols or tertiary alcohols bearing an EWG on the side chain were instead carried out in acetonitrile by using an immobilized laccase preparation. Dehydro-Jasmone, dehydro-Hedione, dehydro-Muscone and other fragrance precursors were directly prepared with this procedure, while a synthetic route was developed to easily transform a cyclopentenone derivative into trans-Magnolione and dehydro-Magnolione. The rearrangement of exocyclic allylic alcohols was tested as well, and a dynamic kinetic resolution was observed: α,β-unsaturated ketones with (E)-configuration and a high diastereomeric excess were synthesized. Finally, the 2,2,6,6-tetramethyl-1-piperidinium tetrafluoroborate (TEMPO+BF4?)/laccase catalysed oxidative rearrangement was combined with the ene-reductase/alcohol dehydrogenase cascade process in a one-pot three-step synthesis of cis or trans 3-methylcyclohexan-1-ol, in both cases with a high optical purity. (Figure presented.).
Optically active tertiary alcohols by biocatalysis
?zdemirhan, Devrim
, p. 629 - 645 (2017/03/27)
Initially, chemoenzymatic route to optically active aromatic ring-fused cyclic tertiary alcohols (S)-(–)-1-methyl-1,2,3,4-tetrahydronaphthalen-1-ol-(–)-1b, (S)-(+)-1-methyl-2,3-dihydro-1H-inden-1-ol-(+)-1a has been reported.[9] CAL-A (lipase-A from Candida antarctica) was found the best biocatalyst for 1b, CAL-A cross linked enzyme aggregate (CLEA) for 1a, with ee values of 20 and 45% and the esters 2b and 2a with ee values 99 and 71%. Then, cyclopent-2-ene anchored tertiary allyl 1a′, homoallyl 1b′ and homopropargyl 1c alcohols have been enzymaticly resolved in a high ee (up to 90%) with 44, 40, and 43% chemical yield, respectively, cyclohex-2-ene anchored tertiary allyl 3a, homoallyl 3b, and homopropargyl 3c alcohols in high ee (up to 97%) too with 42, 45, and 49% chemical yield in turn. Chiral dienes yield the spirocyclic dihydropyrans through ring-closing methathesis with 74 and 78% chemical yields with 90 and 97% ee. Chiral enynes afford the cyclopentenone pyrans through Pauson–Khand reaction with 80 and 81% chemical yields as single diastereomers as reported subsequently.[1a]
Chemoenzymatic route to various spirocyclic compounds based on enantiomerically enriched tertiary allylic, homoallylic, and homopropargylic alcohols
Tanyeli, Cihangir,Oezdemirhan, Devrim
, p. 658 - 666 (2014/05/20)
A ring closing metathesis (RCM) reaction of dienes and an intramolecular Pauson-Khand (PKR) reaction of enynes derived from tertiary allyl, homoallyl, and homopropargyl alcohol backbones to afford the corresponding spirocyclic dihydrofuran and dihydropyra
Boronic acid catalyzed Friedel-Crafts reactions of allylic alcohols with electron-rich arenes and heteroarenes
McCubbin, J. Adam,Hosseini, Hamidreza,Krokhin, Oleg V.
supporting information; experimental part, p. 959 - 962 (2010/04/30)
(Chemical Equation Presented) Pentafluorophenylboronic acid catalyzes the regioselective coupling of structurally diverse allylic alcohols with a variety of electron-rich aromatic and heteroaromatic substrates under ambient conditions. The commercially av
Intramolecularly competitive Ireland-Claisen rearrangements: Scope and potential applications to natural product synthesis
Hong, Sang-Phyo,Lindsay, Harriet A.,Yaramasu, Tripura,Zhang, Xiaowei,McIntosh, Matthias C.
, p. 2042 - 2055 (2007/10/03)
A variety of bis-allylic esters were prepared by vinylmetal addition to cycloalkenones followed by esterification either in situ or in a separate operation. For chiral cyclohexenones, the vinyl additions generally occurred with > 10:1 diastereoselectivity. Although in some cases the bis-allylic esters proved to be sensitive to silica gel or other adsorbents, all of the esters examined could be isolated in acceptable purity. The Ireland-Claisen rearrangement of the bis-allylic esters occurred with complete regioselectivity via the exocyclic alkene. The alkene stereochemistry and the stereochemistry at C-2 and C-3 of the pentenoic acid products were consistent with a chairlike transition state in the rearrangement. Substituents at the carbons adjacent to the allylic carbinol carbon (i.e., C-2 or C-6 in cyclohexenone-derived substrates) directed the stereochemical course of the rearrangement. The rearrangements generally proceeded so as to place the larger of the C-2 or C-6 substituents in the pseudoequatorial position with respect to the chairlike transition state. For a bis-allylic ester bearing both a C-2-CH3 and a C-6-OMEM substituent, the rearrangement product resulted from the nominally smaller OMEM substituent occupying a pseudoequatorial position with respect to the chairlike transition state.
Beryllium dichloride: Efficient promoter for the addition of organolithiums and organomagnesiums to cyclohexen-2-one
Krief, Alain,De Vos, Marie Joelle,De Lombart, Stephane,Bosret, Jean,Couty, Francois
, p. 6295 - 6298 (2007/10/03)
Organoberyllium compounds, generated by transmetallation from Grignard and organolithium reagents react with 2-cyclohexenone to give predominantly the adducts resulting from conjugated addition. The chemoselectivity of this reaction was found to be highly dependent upon the nature of organic moiety and of the conditions used.
1,3-Oxidative Rearrangements of Dienols
Majetich, George,Condon, Stephen,Hull, Kenneth,Ahmad, Saeed
, p. 1033 - 1036 (2007/10/02)
Oxidation of 1-vinyl-2-cycloalken-1-ols with PDC regiospecifically affords conjugated dienones in moderate to good yields.
