827-69-0Relevant articles and documents
Lithium(1+)-catalyzed nazarov-type cyclization of 1-arylbuta-2,3-dien-1- ols: Synthesis of benzofulvene derivatives
Sai, Masahiro,Matsubara, Seijiro
, p. 2067 - 2071 (2014)
Lithium hexafluorophosphate proved to be an effective catalyst for a Nazarov-type cyclization of 1-arylbuta-2,3-dien-1-ols to afford benzofulvenes, valuable as building blocks for functional materials and bioactive compounds. Georg Thieme Verlag Stuttgart New York.
Alcohol Dehydrogenases and N-Heterocyclic Carbene Gold(I) Catalysts: Design of a Chemoenzymatic Cascade towards Optically Active β,β-Disubstituted Allylic Alcohols
González-Granda, Sergio,Lavandera, Iván,Gotor-Fernández, Vicente
, p. 13945 - 13951 (2021/04/22)
The combination of gold(I) and enzyme catalysis is used in a two-step approach, including Meyer–Schuster rearrangement of a series of readily available propargylic alcohols followed by stereoselective bioreduction of the corresponding allylic ketone intermediates, to provide optically pure β,β-disubstituted allylic alcohols. This cascade involves a gold N-heterocyclic carbene and an enzyme, demonstrating the compatibility of both catalyst types in aqueous medium under mild reaction conditions. The combination of [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene][bis(trifluoromethanesulfonyl)-imide]gold(I) (IPrAuNTf2) and a selective alcohol dehydrogenase (ADH-A from Rhodococcus ruber, KRED-P1-A12 or KRED-P3-G09) led to the synthesis of a series of optically active (E)-4-arylpent-3-en-2-ols in good yields (65–86 %). The approach was also extended to various 2-hetarylpent-3-yn-2-ol, hexynol, and butynol derivatives. The use of alcohol dehydrogenases of opposite selectivity led to the production of both allyl alcohol enantiomers (93->99 % ee) for a broad panel of substrates.
Highly Enantioselective Iridium-Catalyzed Hydrogenation of Conjugated Trisubstituted Enones
Peters, Bram B. C.,Jongcharoenkamol, Jira,Krajangsri, Suppachai,Andersson, Pher G.
supporting information, p. 242 - 246 (2021/01/13)
Asymmetric hydrogenation of conjugated enones is one of the most efficient and straightforward methods to prepare optically active ketones. In this study, chiral bidentate Ir-N,P complexes were utilized to access these scaffolds for ketones bearing the stereogenic center at both the α- and β-positions. Excellent enantiomeric excesses, of up to 99%, were obtained, accompanied with good to high isolated yields. Challenging dialkyl substituted substrates, which are difficult to hydrogenate with satisfactory chiral induction, were hydrogenated in a highly enantioselective fashion.
Cobalt-Catalyzed Asymmetric 1,4-Hydroboration of Enones with HBpin
Ren, Xiang,Lu, Zhan
supporting information, p. 8370 - 8374 (2021/11/01)
Herein, a series of new 8-OIQ cobalt complexes were synthesized and used for cobalt-catalyzed chemo- and enantioselective 1,4-hydroboration of enones with HBpin to access chiral β,β-disubstituted ketones with good to excellent chemo- and enantioselectivties. This protocol is operationally simple and shows a broad substrate scope.
Lewis Acid Catalyzed Ring-Opening Reaction of Cyclobutanones towards Conjugated Enones
Gao, Jiqiang,Guo, Ziteng,Li, Zhongjuan,Liu, Chunhui,Liu, Yu,Qiu, Tingtian,Zhang, Min,Zhao, Jinbo
, p. 6111 - 6114 (2021/12/16)
An unprecedented Fe-catalyzed ring-opening reaction of simple cyclobutanones is developed, which provides access to conjugated enones with good functional group tolerance in high yields under mild conditions. The product derivatization and gram-scale expe
Catalytic Asymmetric Transfer Hydrogenation of trans-Chalcone Derivatives Using BINOL-derived Boro-phosphates
Na, Fei,Lopez, Susana S.,Beauseigneur, Alice,Hernandez, Lucas W.,Sun, Zhuoxin,Antilla, Jon C.
supporting information, p. 5953 - 5957 (2020/08/12)
Chiral phosphoric-acid-catalyzed asymmetric reductions of trans-chalcones have been investigated in this work. A BINOL-derived boro-phosphate-catalyzed asymmetric transfer hydrogenation of the carbon-carbon double bond of trans-chalcone derivatives employing borane as a hydride source was realized. This methodology provides a convenient procedure to access chiral dihydrochalone derivatives in high yields and with high enantioselectivities under mild conditions.
Capturing the Monomeric (L)CuH in NHC-Capped Cyclodextrin: Cavity-Controlled Chemoselective Hydrosilylation of α,β-Unsaturated Ketones
Bistri-Aslanoff, Olivia,Derat, Etienne,Leloux, Sébastien,Leyssens, Tom,Ménand, Micka?l,Meijide Suárez, Jorge,Riant, Olivier,Roland, Sylvain,Sollogoub, Matthieu,Xu, Guangcan,Zhang, Pinglu,Zhang, Yongmin
supporting information, p. 7591 - 7597 (2020/03/23)
The encapsulation of copper inside a cyclodextrin capped with an N-heterocyclic carbene (ICyD) allowed both to catch the elusive monomeric (L)CuH and a cavity-controlled chemoselective copper-catalyzed hydrosilylation of α,β-unsaturated ketones. Remarkably, (α-ICyD)CuCl promoted the 1,2-addition exclusively, while (β-ICyD)CuCl produced the fully reduced product. The chemoselectivity is controlled by the size of the cavity and weak interactions between the substrate and internal C?H bonds of the cyclodextrin.
Chiral 1,3,2-Diazaphospholenes as Catalytic Molecular Hydrides for Enantioselective Conjugate Reductions
Miaskiewicz, Solène,Reed, John H.,Donets, Pavel A.,Oliveira, Caio C.,Cramer, Nicolai
, p. 4039 - 4042 (2018/03/13)
Secondary 1,3,2-diazaphospholenes have a polarized P?H bond and are emerging as molecular hydrides. Herein, a class of chiral, conformationally restricted methoxy-1,3,2-diazaphospholene catalysts is reported. We demonstrate their catalytic potential in asymmetric 1,4-reductions of α,β-unsaturated carbonyl derivatives, including enones, acyl pyrroles, and amides, which proceeded in enantioselectivities of up to 95.5:4.5 e.r.
The synthesis of non-racemic β-alkyl-β-aryl-disubstituted allyl alcohols and their transformation into allylamines and amino acids bearing a quaternary stereocenter
Narczyk, Aleksandra,Pieczykolan, Micha?,Stecko, Sebastian
, p. 3921 - 3946 (2018/06/08)
A synthesis of non-racemic β-alkyl-β-aryl allyl alcohols and their transformation into allylamines bearing a quaternary stereogenic center is reported. The allyl alcohols were prepared either by Cu-catalyzed enantioselective reduction of enones or by sequ
Copper(II)-Catalyzed Tandem Decarboxylative Michael/Aldol Reactions Leading to the Formation of Functionalized Cyclohexenones
Lee, Jeonghyo,Wang, Sibin,Callahan, Miranda,Nagorny, Pavel
supporting information, p. 2067 - 2070 (2018/04/16)
This work describes the development of a new single-pot copper(II)-catalyzed decarboxylative Michael reaction between β-keto acids and enones, followed by in situ aldolization, which results in highly functionalized chiral and achiral cyclohexenones. The achiral version of this Robinson annulation features a hitherto unprecedented Michael reaction of β-keto acids with sterically hindered β,β′-substituted enones and provides access to all carbon quaternary stereocenter-containing cyclohexenones (11 examples, 43-83% yield). In addition, an asymmetric chiral bis(oxazoline) copper(II)-catalyzed single-pot Robinson annulation has been devised for preparing chiral cyclohexenones, including some products that contain vicinal stereocenters (5 examples, 65-85% yield, 84-94% ee). This latter protocol has been successfully applied to the enantioselective formation of the oxygenated 10-nor-steroid core from readily available starting materials.
