Recent advances in C(sp³)–H bond functionalization via metal–carbene insertions

• Bo Wang,
• Di Qiu,
• Yan Zhang and
• Jianbo Wang

Beilstein J. Org. Chem. 2016, 12, 796–804, doi:10.3762/bjoc.12.78

• development of intermolecular C–H insertion in the application of C(sp3)–H bond functionalizations, especially for light alkanes, is reviewed. The challenging problem of regioselectivity in C–H bond insertions has been tackled by the use of sterically bulky metal catalysts, such as metal porphyrins and silver

• –carbene; site-selectivity; Introduction Direct functionalization of inactivated C–H bonds, especially C(sp3)–H bonds, have attracted significant attentions in recent years. The C(sp3)–H bond activation strategies based on radical reactions and transition metal catalysis have been explored, alongside the

• development of various directing groups for controlling the site-selectivity of the reaction. Regardless of the great efforts devoted to the field, the intermolecular C(sp3)–H bond activation of simple alkanes still remains a formidable challenge, obviously attributed to the inertness and ubiquitous nature of

Cascade alkylarylation of substituted N-allylbenzamides for the construction of dihydroisoquinolin-1(2H)-ones and isoquinoline-1,3(2H,4H)-diones

• Ping Qian,
• Bingnan Du,
• Wei Jiao,
• Haibo Mei,
• Jianlin Han and
• Yi Pan

Beilstein J. Org. Chem. 2016, 12, 301–308, doi:10.3762/bjoc.12.32

• )-diones in good yield. Keywords: C(sp3)–H bond functionalization; cyclization; dihydroisoquinolin-1(2H)-one; N-allylbenzamides; oxidation; Introduction The direct and selective functionalization of an unactivated sp3 C–H bond, which belongs to an effective strategic approach in green and sustainable

• (Scheme 5c). This discloses that the cleavage of the C(sp3)−H bond to form the radical may be involved in the turnover-limiting steps of this procedure. Based on the previous radical cyclization reactions [44][47][48] and the results obtained above, a plausible mechanism accounting for this cascade

• bonds and cyclization reactions of N-substituted allylbenzamides were developed. The reaction involved cleavage of the C(sp3)–H bond, alkylation and intramolecular cyclization, affording the 4-alkyl-substituted dihydroisoquinolin-1(2H)-one derivatives with moderate to good chemical yield. The

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

• sulfonamidation and imidation) reactions under the categories of C(sp3)–H bond amidation, C(sp2)–H bond amidation, C(sp)–H bond amidation and cascade reactions initiated by C–H amidation. Review C(sp3)–H bond amidation Intermolecular amidation The formation of N-alkylamides could be traditionally accessed via

• sulfoximine derivatives (Scheme 7). Intramolecular amidation Comparing with the intermolecular amidation, the copper-catalyzed intramolecular version of the sp3C–H amidation was much less explored. In 2014, Kuninobu and Kanai et al. [52] reported an unprecedented intramolecular C(sp3)–H bond amidation for the

C–H bond halogenation catalyzed or mediated by copper: an overview

• Wenyan Hao and
• Yunyun Liu

Beilstein J. Org. Chem. 2015, 11, 2132–2144, doi:10.3762/bjoc.11.230

• via direct C–H bond transformation is reviewed. Keywords: C(sp2)–H bond; C(sp3)–H bond; copper; halogenation; Introduction Organohalides are inarguably a class of most useful chemicals owing to their prevalent application in the synthesis of organic products. The versatile reactivity of C–X bonds

• 67 was found to be capable of undertaking a formal alkene chlorination to provide chlorine-functionalized product 68 as mixed Z/E isomers (Scheme 22). Halogenation of the C(sp3)–H bond Compared with the C(sp2)–H bond, the C(sp3)–H bond is the less acidic one and is therefore known as the most

• challenging chemical bond for direct activation. Consequently, the examples on copper-catalyzed halogenation of inactive C(sp3)–H bond remained barely explored. In 2010, Ball and Kundu [68] developed a protocol of remote C–H chlorination of alkyl hydroperoxides by means of copper catalysis. As displayed in

Cross-dehydrogenative coupling for the intermolecular C–O bond formation

• Igor B. Krylov,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2015, 11, 92–146, doi:10.3762/bjoc.11.13

Lewis acid-catalyzed redox-neutral amination of 2-(3-pyrroline-1-yl)benzaldehydes via intramolecular [1,5]-hydride shift/isomerization reaction

• Chun-Huan Jiang,
• Xiantao Lei,
• Le Zhen,
• Hong-Jin Du,
• Xiaoan Wen,
• Qing-Long Xu and
• Hongbin Sun

Beilstein J. Org. Chem. 2014, 10, 2892–2896, doi:10.3762/bjoc.10.306

• : catalysis; C–H activation; hydride-shift; Lewis acid; redox reaction; Introduction The direct and selective functionalization of the inactive C(sp3)–H bond constitute an economically attractive strategy for organic syntheses [1][2][3][4][5][6][7][8][9][10]. Until now, a number of transition metals can be

Preparation of neuroprotective condensed 1,4-benzoxazepines by regio- and diastereoselective domino Knoevenagel–[1,5]-hydride shift cyclization reaction

• László Tóth,
• Yan Fu,
• Hai Yan Zhang,
• Attila Mándi,
• Katalin E. Kövér,
• Tünde-Zita Illyés,
• Attila Kiss-Szikszai,
• Balázs Balogh,
• Tibor Kurtán,
• Sándor Antus and
• Péter Mátyus

Beilstein J. Org. Chem. 2014, 10, 2594–2602, doi:10.3762/bjoc.10.272

• neuroprotective condensed 2-phenyl-1,4-benzoxazepines rac-7a,b through the diastereoselective domino Knoevenagel–1,5-hydride shift cyclization reaction rac-5→rac-7a,b from the readily available 4-aryl-2-phenyl-1,4-benzoxazepine derivative, rac-5 (Scheme 1). Ring-closure transformations involving C(sp3)–H bond

• (sp3)–H bond α to a tertiary amine nitrogen through [1,5]-hydride shift (rac-6→A) (Scheme 1) to afford the zwitterionic intermediate A and (2) subsequent 6-endo cyclization (A→rac-7a,b). The stereoselective version of “tert-amino effect” induced cyclization using chiral metal-catalyzed [12][13][14][15

• functionalization in an internal redox process, particularly involving C–H bonds in α-position to a tertiary amine nitrogen atom, has attracted considerable attention due to its synthetic potential [7][8][9][10][11]. The intramolecular “tert-amino effect” induced cyclization consists in (1) the cleavage of the C

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• agostic A10a or pure empty site T4a,b. In the case of It-Bu ligand [44], a similar cyclometalation reaction is observed even at low temperatures (−70 °C), but the putative methyl intermediate could not be detected. The agostic complex A9 can exchange the site of cyclometalation by C(sp3)–H bond activation