Morita–Baylis–Hillman reaction of 3-formyl-9H-pyrido[3,4-b]indoles and fluorescence studies of the products

• Nisha Devi and
• Virender Singh

Beilstein J. Org. Chem. 2022, 18, 926–934, doi:10.3762/bjoc.18.92

• and substituents was also studied during investigation of fluorescence properties of these derivatives. Keywords: β-carboline; DABCO; fluorescence; MBH reaction; Michael addition; structure–fluorescence activity relationship; Introduction Among the polycyclic alkaloids based on indole, the tricyclic

• medicinal importance is the reason that the synthesis of β-carboline-containing derivatives has been an exciting area for researchers [34][35][36][37][38][39][40]. The Morita–Baylis–Hillman (MBH) reaction is an astonishing C–C bond forming reaction between a carbonyl electrophile and an activated alkene

• leading to the formation of allylic alcohol; a highly functionalized product [41][42][43][44]. The chemistry of the MBH reaction is decorated with several unique features viz. atom economy, complexity generation and generation of a chiral center from a pro-chiral electrophile. The chemistry of the MBH

Mechanochemical synthesis of small organic molecules

• Tapas Kumar Achar,
• Anima Bose and
• Prasenjit Mal

Beilstein J. Org. Chem. 2017, 13, 1907–1931, doi:10.3762/bjoc.13.186

• –Hillman reaction The Morita–Baylis–Hillman reaction (MBH) employs olefins, tertiary amine catalysts and electrophile aldehydes to produce multifunctional products. Mack et al., found a significant enhancement in the rate of a Morita–Baylis–Hillman (MBH) reaction under ball milling conditions (Scheme 5

• -(S)-proline derived catalyst [49]. b) Report using α,α-dipeptide-based catalyst [50]. Mechanochemical Michael reaction [51]. Mechanochemical organocatalytic asymmetric Michael reaction [52]. Mechanochemical Morita–Baylis–Hillman (MBH) reaction [53]. Mechanochemical Wittig reactions [55

Catalytic asymmetric synthesis of biologically important 3-hydroxyoxindoles: an update

• Bin Yu,
• Hui Xing,
• De-Quan Yu and
• Hong-Min Liu

Beilstein J. Org. Chem. 2016, 12, 1000–1039, doi:10.3762/bjoc.12.98

• . found that β-isocupreidine (β-ICD, cat. 22) can efficiently catalyze the Morita–Baylis–Hillman (MBH) reaction of isatins with maleimides to generate the 3-substituted 3-hydroxyoxindoles in excellent yields (up to 96% yield) and with excellent enantioselectivity (up to >99% ee) under mild conditions

Cupreines and cupreidines: an established class of bifunctional cinchona organocatalysts

• Laura A. Bryant,
• Rossana Fanelli and
• Alexander J. A. Cobb

Beilstein J. Org. Chem. 2016, 12, 429–443, doi:10.3762/bjoc.12.46

• a cinchona organocatalyst with a 6’-OH functionality came from Hatakeyama and co-workers in 1999 who demonstrated the use of β-ICPD in an asymmetric Morita–Baylis–Hillman (MBH) reaction [15][16][17][18] what is essentially an asymmetric C3-substituted ammonium enolate reaction (Scheme 1) [19][20

• processes, the tertiary amine adds into the conjugate ester as with the MBH reaction, but instead of the resulting C3-ammonium enolate reacting with an electrophile, an E1cB elimination of the carbonate occurs to generate another conjugated system. This can then undergo an attack by a Michael donor

• been developed by Frontier and co-worker using β-ICPD through a mechanism that is reminiscent of the MBH reaction (Scheme 7) [31]. In this process however, the tertiary amine adds to the conjugated system 25 in a 1,6-fashion to generate intermediate enolate 26. This undergoes a single bond rotation to

Application of 7-azaisatins in enantioselective Morita–Baylis–Hillman reaction

• Qing He,
• Gu Zhan,
• Wei Du and
• Ying-Chun Chen

Beilstein J. Org. Chem. 2016, 12, 309–313, doi:10.3762/bjoc.12.33

• reaction; Introduction The asymmetric Morita–Baylis–Hillman (MBH) reaction is one of the most powerful synthetic methods in organic chemistry, as it directly constructs carbon–carbon bonds in an atom-economical manner and provides densely functionalized molecules [1][2][3][4]. In particular, the direct

• formation of stereogenic quaternary carbon centers by enantioselective MBH reactions has been a fascinating and challenging area, because the compatible electrophiles are always limited to aldehydes or derivatives thereof. Since the first elegant work on the enantioselective MBH reaction between isatins and

• stereocontrol [6][7][8][9][10][11][12]. Maleimides are also good nucleophilic precursors in the MBH reactions and in 2013, Chimni developed an asymmetric MBH reaction of isatins and maleimides with excellent enantioselectivity [13]. Later, the same group expanded this strategy to isatin-derived ketimines under

Morita–Baylis–Hillman reaction of acrylamide with isatin derivatives

• Radhey M. Singh,
• Kishor Chandra Bharadwaj and
• Dharmendra Kumar Tiwari

Beilstein J. Org. Chem. 2014, 10, 2975–2980, doi:10.3762/bjoc.10.315

• with acrylate and acrylonitrile has also been developed resulting in high product yields. Keywords: acrylamide; isatin; ketimine; Morita–Baylis–Hillman; phenol; Introduction The Morita–Baylis–Hillman (MBH) reaction is an important carbon–carbon bond-forming reaction [1][2][3]. It involves the

• . [13] used dioxane/water in a 1:1 ratio, while Aggarwal et al. [14] used quinuclidine in methanol to carry out the MBH reaction of acrylamide. Connon et al. [15] utilized phenol and/or a H2O/t-BuOH 7:3 system for rate acceleration and Guo et al. used aryl activation [16][17]. Other reports made use of

• appending other functionalities/groups for intramolecular transformations. Other reports have used this feature for the development of an intramolecular MBH reaction: Corey et al. (total synthesis) [29], Pigge et al. (ruthenium complexes as an electrophile) [30], and Basavaiah et al. [31][32]. Isatin has

Mechanochemistry assisted asymmetric organocatalysis: A sustainable approach

• Pankaj Chauhan and
• Swapandeep Singh Chimni

Beilstein J. Org. Chem. 2012, 8, 2132–2141, doi:10.3762/bjoc.8.240

• catalyst activates and orients the β-ketoester. Morita–Baylis–Hillman (MBH) reaction The Morita–Baylis–Hillman (MBH) reaction provides a very useful and interesting method for the synthesis of β-hydroxycarbonyl compounds with an α-alkylidene group [49][50][51][52][53]. Mechanochemical methods of neat

• organocatalysts in an enantioselective MBH reaction and as cyanide ion sensors in organic solvents. Chiral bis-thiourea XI catalyses the MBH reaction of benzaldehyde (2b) and 2-cyclohexen-1-one (15) to provide MBH adduct 16 in 70% yield and 24% ee under neat grinding and LAG. Anhydride ring opening The

• Michael reaction assisted by pestle and mortar grinding. C-2 symmetric thiourea catalysed enantioselective MBH reaction. Quinine-catalysed ring opening of meso-anhydride by ball-milling. Ball-milling-assisted (A) synthesis of glycine schiff bases and (B) their organocatalytic asymmetric alkylation

Reactions of nitroxides XIII: Synthesis of the Morita–Baylis–Hillman adducts bearing a nitroxyl moiety using 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl as a starting compound, and DABCO and quinuclidine as catalysts

• Jerzy Zakrzewski

Beilstein J. Org. Chem. 2012, 8, 1515–1522, doi:10.3762/bjoc.8.171

• aldehydes. Keywords: 4-acryloyloxy-2,2,6,6-tetramethylpiperidine-1-oxyl; DABCO; Morita–Baylis–Hillman reaction; nitroxides; quinuclidine; Introduction In the Morita–Baylis–Hillman (MBH) reaction, aldehydes react with a double bond activated by an electron-withdrawing group (EWG). The vinylic carbon

• phosphine [19] as a catalyst. The MBH reaction is a carbon–carbon bond forming process. This is the reason why a huge amount of research devoted to the reaction is reported every year. The application and scope of the reaction has been summarized in many review articles, e.g., [20], as well as the latest

• ones [21][22][23][24]. Some recent results concerning MBH reaction have been presented [6][16][18][25][26][27][28][29][30][31][32][33]. MBH adducts themselves are reported to be antiproliferative agents [34]; however, they are often applied as a tool for building more complex target structures, usually

Chiral multifunctional thiourea-phosphine catalyzed asymmetric [3 + 2] annulation of Morita–Baylis–Hillman carbonates with maleimides

• Hong-Ping Deng,
• De Wang,
• Yin Wei and
• Min Shi

Beilstein J. Org. Chem. 2012, 8, 1098–1104, doi:10.3762/bjoc.8.121

• was shown that chiral multifunctional thiourea-phosphines were excellent catalysts for the asymmetric aza-MBH reaction, asymmetric allylic substitution of MBH adducts, and asymmetric [3 + 2] annulation of MBH carbonates with electron-deficient olefins [52][53][54][55][56]. Hence, we initially used