Earth-abundant 3d transition metals on the rise in catalysis

• Nikolaos Kaplaneris and
• Lutz Ackermann

Beilstein J. Org. Chem. 2022, 18, 86–88, doi:10.3762/bjoc.18.8

• , Germany 10.3762/bjoc.18.8 Keywords: C–H activation; 3d transition metals; green chemistry; late-stage functionalization; sustainability; Transition metal catalysis has emerged as a transformative platform for the assembly of increasingly complex compounds, with enabling applications to natural product

• . Applications of this strategy range from late-stage functionalization to modern photocatalysis and electrocatalysis, with contributions from around the globe, including Brazil, China, Japan, Germany, India, and South Korea, among others. The increasing use of C–H activations in academic and industrial

Iron-catalyzed domino coupling reactions of π-systems

• Austin Pounder and
• William Tam

Beilstein J. Org. Chem. 2021, 17, 2848–2893, doi:10.3762/bjoc.17.196

• applicability in late-stage functionalization. The Bao group has since demonstrated many other carbon-centered radicals were amenable in the carboazidation reaction of alkenes including diacylperoxides [133] and aldehydes [134]. In 2021, the Bao group followed up on their previous work and developed an

On the application of 3d metals for C–H activation toward bioactive compounds: The key step for the synthesis of silver bullets

• Renato L. Carvalho,
• Amanda S. de Miranda,
• Mateus P. Nunes,
• Roberto S. Gomes,
• Guilherme A. M. Jardim and
• Eufrânio N. da Silva Júnior

Beilstein J. Org. Chem. 2021, 17, 1849–1938, doi:10.3762/bjoc.17.126

• . The photo-electro methodology allowed the late-stage functionalization of valuable bioactive molecules, and the structures of a adapalene precursor (65) and ibuprofen derivative (66) were successfully azidated in moderate yields (Scheme 23C). Some silylated compounds like 67 have proven to be

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• biologically active small molecules and complex peptides. Keywords: bioactive molecules; 3d transition metals; late-stage functionalization; manganese catalyst; sustainable catalysis; Introduction Manganese, a 3d transition metal, allows for a potentially ideal sustainable catalytic system because of the

• assistance. However, application of this protocol for late-stage functionalization remains challenging [96][97][98][99][100][101][102][103]. In 2021, it was revealed by the Ackermann group that manganese(I) catalysis enabled the bioorthogonal late-stage alkenylation of structurally sophisticated peptides

• -containing peptide 37g. Conclusion Metal-catalyzed late-stage functionalization has shown significant potential in the fields of medicinal chemistry, agrochemistry, and chemical biology. While transition metal catalysis has been a reliable and efficient strategy for late-stage functionalization, it suffers

Copper-mediated oxidative C−H/N−H activations with alkynes by removable hydrazides

• Feng Xiong,
• Bo Li,
• Chenrui Yang,
• Liang Zou,
• Wenbo Ma,
• Linghui Gu,
• Ruhuai Mei and
• Lutz Ackermann

Beilstein J. Org. Chem. 2021, 17, 1591–1599, doi:10.3762/bjoc.17.113

• : benzhydrazides; copper; 3-methyleneisoindolin-1-one; removable directing group; Introduction Inexpensive copper-promoted oxidative C−H activations [1][2][3][4][5][6][7][8][9][10][11] have been recognized as competent tools for the efficient assembly and late-stage functionalization of organic molecules due to

Methodologies for the synthesis of quaternary carbon centers via hydroalkylation of unactivated olefins: twenty years of advances

• Thiago S. Silva and
• Fernando Coelho

Beilstein J. Org. Chem. 2021, 17, 1565–1590, doi:10.3762/bjoc.17.112

• substrates (Scheme 2 and Scheme 4), and an external proton source (acetic acid) was required to furnish the hydroalkylated products 7 (Scheme 5A). The quaternary carbon centers were synthetized in moderate to excellent yields by this methodology, and its potential use in late-stage functionalization was

• methanol and gentle heating was necessary to optimize the formation of 75 from 74. As is usual in these Mukaiyama-like reaction conditions, the developed hydromethylation tolerated an array of functional groups and the late-stage functionalization of complex natural products (75e–g). Deuterated and other

Photosensitized direct C–H fluorination and trifluoromethylation in organic synthesis

• Shahboz Yakubov and
• Joshua P. Barham

Beilstein J. Org. Chem. 2020, 16, 2151–2192, doi:10.3762/bjoc.16.183

• of aryl triflates [29] and arylpalladium complexes [2][47], few permit a one-step transformation of unactivated C(sp3)–H bonds to C(sp3)–F bonds [1][3][36][38][48]. Such a transformation would be highly valuable for the late-stage functionalization (LSF) of complex molecules, such as those in Scheme

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

• outcome is interesting from the sophisticated molecule late-stage functionalization viewpoint. Furthermore, the quantum yield of the reaction was measured and turned out to be 6.5. This result indicated that the mechanism of this reaction involved a short radical chain process [85]. The same year, a

Functionalization of the imidazo[1,2-a]pyridine ring in α-phosphonoacrylates and α-phosphonopropionates via microwave-assisted Mizoroki–Heck reaction

• Damian Kusy,
• Agata Wojciechowska,
• Joanna Małolepsza and
• Katarzyna M. Błażewska

Beilstein J. Org. Chem. 2020, 16, 15–21, doi:10.3762/bjoc.16.3

• ]pyridine ring has been synthesized via the microwave-assisted Mizoroki–Heck reaction. The efficient modification of the imidazo[1,2-a]pyridine ring has been achieved as late-stage functionalization, enabling and accelerating the generation of a library of compounds from a common precursor. Keywords: α

• overrated [1]. However, as is true for many reactions, the late-stage functionalization of target compounds or their advanced intermediates is rarely an extension of reaction conditions developed for structurally simple analogs. The late-stage approach is especially desirable in the synthesis of a library

Synthesis and characterization of bis(4-amino-2-bromo-6-methoxy)azobenzene derivatives

• David Martínez-López,
• Amirhossein Babalhavaeji,
• Diego Sampedro and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2019, 15, 3000–3008, doi:10.3762/bjoc.15.296

• substituent in an attempt to enhance water solubility. Late-stage functionalization of the ortho-position was carried out through a palladium(II)-catalyzed C–H activation, resulting in ortho-brominated azobenzenes [21]. Photochemical characterization Despite the morpholino substituent, compound 4 was found to

Recent advances in transition-metal-catalyzed incorporation of fluorine-containing groups

• Xiaowei Li,
• Xiaolin Shi,
• Xiangqian Li and
• Dayong Shi

Beilstein J. Org. Chem. 2019, 15, 2213–2270, doi:10.3762/bjoc.15.218

Synthesis of pyrrolidine-based hamamelitannin analogues as quorum sensing inhibitors in Staphylococcus aureus

• Jakob Bouton,
• Kristof Van Hecke,
• Reuven Rasooly and
• Serge Van Calenbergh

Beilstein J. Org. Chem. 2018, 14, 2822–2828, doi:10.3762/bjoc.14.260

• , CH2Cl2, 0 °C; l) conc. HCl, MeOH/H2O 1:1, reflux. Late stage functionalization of the pyrrolidine nitrogen. Reagents and conditions: A) (masked) aldehyde, NaBH3CN, AcOH, MeOH, 60 °C; B) MeI, DIPEA, THF, 0 °C; C) Ms-Cl, Et3N, THF, 0 °C; D) AcOH, DIPEA, HATU, DMF, rt. Supporting Information Supporting

DABCO- and DBU-promoted one-pot reaction of N-sulfonyl ketimines with Morita–Baylis–Hillman carbonates: a sequential approach to (2-hydroxyaryl)nicotinate derivatives

• Soumitra Guin,
• Raman Gupta,
• Debashis Majee and
• Sampak Samanta

Beilstein J. Org. Chem. 2018, 14, 2771–2778, doi:10.3762/bjoc.14.254

• as the requirement of high temperatures or use of strong oxidants (H2O2, oxone, K2S2O8, TBHP, PIDA, NHPI etc.) that are not much compatible with functionality, precluding late-stage functionalization. Moreover, the scope of substitution on the pyridine ring is limited which in turn hampers the

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• method tolerates the presence of pyridine derivatives, alcohols, esters, carboxylic acids, Boc-protected amines, boronic pinacol esters and was applied to the late-stage functionalization of complex molecules. In 2016, the first metal-free photoredox-catalyzed radical thiol–yne reaction was reported by

• diaryliodonium salts reacted efficiently with alkyl and aryl thiosulfate salts to the respective sulfide and sulfoxides. A row of functional groups like for example amines, cyano groups, esters, hydroxy groups or nitro groups were highly tolerated and gave the opportunity for late-stage functionalization of

Versatile synthesis of the signaling peptide glorin

• Robert Barnett,
• Daniel Raszkowski,
• Thomas Winckler and
• Pierre Stallforth

Beilstein J. Org. Chem. 2017, 13, 247–250, doi:10.3762/bjoc.13.27

• previous syntheses is that ours allows for late-stage functionalization of the α-amino group of the glutamic acid moiety. This is particularly useful for the rapid generation of different α-amide analogues. Biological activity of glorin and glorinamide The bioactivities of synthetic glorin (1) and

Chiral cyclopentadienylruthenium sulfoxide catalysts for asymmetric redox bicycloisomerization

• Barry M. Trost,
• Michael C. Ryan and
• Meera Rao

Beilstein J. Org. Chem. 2016, 12, 1136–1152, doi:10.3762/bjoc.12.110

• tolerate many sensitive functional groups, such as free alcohols, silyl enol ethers, and ketones, which makes it an attractive metal for late stage functionalization and elaboration of complex molecules. It is thought that the origin of ruthenium’s divergent behavior stems from a difference in reaction

Diversity-oriented synthesis of analogues of the novel macrocyclic peptide FR-225497 through late stage functionalization

• Jyotiprasad Mukherjee,
• Suman Sil and
• Shital Kumar Chattopadhyay

Beilstein J. Org. Chem. 2015, 11, 2487–2492, doi:10.3762/bjoc.11.270

• which involves a late-stage functionalization of a macrocyclic scaffold through cross metathesis in an attempt to create diversity. The utility of this protocol is demonstrated through the preparation of three structural analogues of the important naturally occurring histone deacetylase inhibitor FR

Flexible synthesis of anthracycline aglycone mimics via domino carbopalladation reactions

• Markus Leibeling and
• Daniel B. Werz

Beilstein J. Org. Chem. 2013, 9, 2194–2201, doi:10.3762/bjoc.9.258

• in 88% overall yield (over two steps). Another approach to non-linear systems utilizes a cobalt-mediated intramolecular [2 + 2 + 2]-cycloaddition of a triyne system 9 leading to the fourfold annulated ring system 10 in only one step [16]. Late stage functionalization led to the anticipated structural