Rearrangements of organic peroxides and related processes

• Ivan A. Yaremenko,
• Vera A. Vil’,
• Dmitry V. Demchuk and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2016, 12, 1647–1748, doi:10.3762/bjoc.12.162

• rearrangement is a protic or Lewis acid-promoted rearrangement of hydroperoxides A resulting in a C–C bond cleavage to form alcohol B and carbonyl compound C (Scheme 50) [313]. The Hock rearrangement is a key step in the cumene process, which is used for the industrial production of phenol (170) and acetone

Base metal-catalyzed benzylic oxidation of (aryl)(heteroaryl)methanes with molecular oxygen

• Hans Sterckx,
• Johan De Houwer,
• Carl Mensch,
• Wouter Herrebout,
• Kourosch Abbaspour Tehrani and
• Bert U. W. Maes

Beilstein J. Org. Chem. 2016, 12, 144–153, doi:10.3762/bjoc.12.16

• anilines resulting in the formation of 2-aryl-α-ketoacetamides was reported by Jiao [22] and a closely related intramolecular variant leading to isatins has been published by Ilangovan [23]. A remarkable Cu-catalyzed chemoselective oxidative C–C bond cleavage of methyl ketones was reported by the group of

Recent highlights in biosynthesis research using stable isotopes

• Jan Rinkel and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2015, 11, 2493–2508, doi:10.3762/bjoc.11.271

• incorporation of labeled Gly into the methyl group was rationalized by glycine degradation, directing the labeling via tetrahydrofolate and SAM into aspirochlorine biosynthesis. The conversion of the Phe residue to Gly may proceed through either oxidative C–C bond cleavage or a retro-aldol reaction in 18, in

Recent advances in copper-catalyzed C–H bond amidation

• Jie-Ping Wan and
• Yanfeng Jing

Beilstein J. Org. Chem. 2015, 11, 2209–2222, doi:10.3762/bjoc.11.240

• ] reported the copper-catalyzed, tert-butyl hydroperoxide (TBHP)-assisted C–H amidation of tertiary amines 1. By heating at 80 °C, the C–H bond in dimethylaniline underwent direct amidation to provide products 3 in the presence of amides 2. On the other hand, the dephenylation transformation via C–C bond

• cleavage took place as the main route when N-phenyl-N-methylaniline was employed as the alternative reactant, which led to the production of 3 as the main products, while corresponding products 4 via C–H bond amidation occurred as the minor ones. Notably, this kind of C–H amidation strategy could be

Copper-catalyzed aerobic radical C–C bond cleavage of N–H ketimines

• Ya Lin Tnay,
• Gim Yean Ang and
• Shunsuke Chiba

Beilstein J. Org. Chem. 2015, 11, 1933–1943, doi:10.3762/bjoc.11.209

• cleavage of N–H ketimines. Treatment of N–H ketimines having an α-sp3 hybridized carbon under Cu-catalyzed aerobic reaction conditions resulted in a radical fragmentation with C–C bond cleavage to give the corresponding carbonitrile and carbon radical intermediate. This radical process has been applied for

• the construction of oxaspirocyclohexadienones as well as in the electrophilic cyanation of Grignard reagents with pivalonitrile as a CN source. Keywords: C–C bond cleavage; copper; ketimines; molecular oxygen; radical; Introduction Alkylideneaminyl radicals (iminyl radicals) have been utilized for

• formation of the desired 6-membered azaspirocycle 3a’ was observed, while oxaspirocyclohexadienone 3a, biaryl alkene 4a, and p-tolunitrile (5a) were isolated in 29%, 32%, and 86% yields, respectively (Scheme 4). Oxaspirocyclohexadienone 3a was formed through C–C bond cleavage from N–H ketimine intermediate

Recent applications of ring-rearrangement metathesis in organic synthesis

• Sambasivarao Kotha,
• Milind Meshram,
• Priti Khedkar,
• Shaibal Banerjee and
• Deepak Deodhar

Beilstein J. Org. Chem. 2015, 11, 1833–1864, doi:10.3762/bjoc.11.199

• syntheses of virgidivarine and virgiboidine by employing an intramolecular ene–ene–yne domino RRM protocol in combination with an oxidative C–C bond cleavage. This protocol opens-up new opportunities for the construction of intricate dipiperidine-based targets in a stereoselective manner (Scheme 12). Lee

Organobase-catalyzed three-component reactions for the synthesis of 4H-2-aminopyrans, condensed pyrans and polysubstituted benzenes

• Moustafa Sherief Moustafa,
• Saleh Mohammed Al-Mousawi,
• Maghraby Ali Selim,
• Ahmed Mohamed Mosallam and
• Mohamed Hilmy Elnagdi

Beilstein J. Org. Chem. 2014, 10, 141–149, doi:10.3762/bjoc.10.11

• propiolate (4a) in the presence of L-proline to produce the penta-substituted benzene derivative 13b in 60% yield (Scheme 4). In order to explain this unusual finding, we proposed that malononitrile, perhaps formed under the reaction conditions by C–C bond cleavage promoted fragmentation of 8, adds to 9 to

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• azodicarboxylates. α-Arylation of amines. Plausible mechanism for α-arylation of amines. Photoinduced C–C bond cleavage of tertiary amines. Photoredox cleavage of C–C bonds of 1,2-diamines. Proposed mechanism photoredox cleavage of C–C bonds. Intermolecular [3 + 2] annulation of cyclopropylamines with olefins

Recent developments in gold-catalyzed cycloaddition reactions

• Fernando López and
• José L. Mascareñas

Beilstein J. Org. Chem. 2011, 7, 1075–1094, doi:10.3762/bjoc.7.124

• authors proposed an initial nucleophilic attack of the carbonyl oxygen on the gold(I)-activated alkyne to form a vinyl–gold intermediate XII, analogous to that previously shown in Scheme 5 (IX). Aromatization of this intermediate through C–C bond cleavage of the oxirane unit, followed by addition of the

Synthetic applications of gold-catalyzed ring expansions

• David Garayalde and
• Cristina Nevado

Beilstein J. Org. Chem. 2011, 7, 767–780, doi:10.3762/bjoc.7.87

• activation of the cyclopropene, cation 55 is formed. C–C bond cleavage of the cyclopropyl ring followed by a Friedel–Crafts reaction affords, after recovery of aromaticity, the observed products [47]. 4 Ring expansions involving annulation reactions Diels–Alder, [1,3]-dipolar-, [2 + 2]- and [4 + 3

Photosonochemical catalytic ring opening of α-epoxyketones

• Hamid R. Memarian and
• Ali Saffar-Teluri

Beilstein J. Org. Chem. 2007, 3, No. 2, doi:10.1186/1860-5397-3-2

• electron transfer reactions by dicyanoanthracene (DCA), [32][33] tetracyanoethylene (TCNE) [34][35] and 2,4,6-triphenylpyrilium tetrafluoroborate. [36][37][38][39][40] In the case of C-C bond cleavage, the generated intermediates from epoxide radical cations have been trapped by molecular oxygen to form