Recent progress in the synthesis of homotropane alkaloids adaline, euphococcinine and N-methyleuphococcinine

• Dimas J. P. Lima,
• Antonio E. G. Santana,
• Michael A. Birkett and
• Ricardo S. Porto

Beilstein J. Org. Chem. 2021, 17, 28–41, doi:10.3762/bjoc.17.4

• from the carbocupration of 85, a Grignard derivative of 1-heptyne [56]. After a lithium–halogen exchange, the corresponding vinyllithium was treated with p-menthane-3-carboxaldehyde to give the isomeric allylalcohols (−)-87a and (−)-87b in a 5:1 ratio. After chromatographic separation, (−)-adaline (1

Diastereo- and enantioselective preparation of cyclopropanol derivatives

• Marwan Simaan and
• Ilan Marek

Beilstein J. Org. Chem. 2019, 15, 752–760, doi:10.3762/bjoc.15.71

• Marwan Simaan Ilan Marek The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, 32000, Israel 10.3762/bjoc.15.71 Abstract The diastereoselective carbocupration reaction of alkoxy-functionalized cyclopropene derivatives

• (or amination) sequence on achiral nonfunctionalized cyclopropenes provided the desired cyclopropanol (and cyclopropylamine) derivatives in excellent diastereo- and enantiomeric excesses. Keywords: carbocupration; cyclopropanol; cyclopropene; regioselectivity; stereoselectivity; Introduction The

• reported on the reactivity of oxenoids [74][75][76][77], indicating that the reaction of a nucleophile with oxenoid proceeds through an SN2 process [74]. Following the carbocupration of cyclopropene 3 into cyclopropylcopper species, the subsequent oxidation with the amphiphilic lithiated hydroperoxide t

Practical tetrafluoroethylene fragment installation through a coupling reaction of (1,1,2,2-tetrafluorobut-3-en-1-yl)zinc bromide with various electrophiles

• Ken Tamamoto,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2018, 14, 2375–2383, doi:10.3762/bjoc.14.213

• -containing organic molecules has a high priority in various research areas. A number of synthetic protocols for CF2CF2-containing molecules have been developed in the last half-decade. Ogoshi and co-workers reported an efficient synthetic protocol for CF2CF2-containing compounds via carbocupration or

Copper-catalyzed stereoselective conjugate addition of alkylboranes to alkynoates

• Takamichi Wakamatsu,
• Kazunori Nagao,
• Hirohisa Ohmiya and
• Masaya Sawamura

Beilstein J. Org. Chem. 2015, 11, 2444–2450, doi:10.3762/bjoc.11.265

• methoxide to form trisubstituted alkenylstannanes [15]. The latter reaction pathway involved Sn-trapping of an alkenylcopper intermediate that was formed through syn-carbocupration of an alkylcopper(I) species across the C–C triple bond of the alkynoate. We envisioned that 1,2-hydroalkylation of the

• ][14][15][20][21][22][23][24][25]. Subsequently, the alkylcopper species B forms a π-complex (C) with alkynoate 3. Then, syn-carbocupration across the C–C triple bond of C with the assistance of Lewis acidic activation with the tert-butoxyborane gave an alkenylcopper intermediate (D). Finally

Regio- and stereoselective carbometallation reactions of N-alkynylamides and sulfonamides

• Yury Minko,
• Morgane Pasco,
• Helena Chechik and
• Ilan Marek

Beilstein J. Org. Chem. 2013, 9, 526–532, doi:10.3762/bjoc.9.57

• carbocupration reactions of heterosubstituted alkynes allow the regio- and stereoselective formation of vinyl organometallic species. N-Alkynylamides (ynamides) are particularly useful substrates for the highly regioselective carbocupration reaction, as they lead to the stereodefined formation of vinylcopper

• alkenes is the carbometallation reaction of alkynes [16][17][18], ynamide should be a suitable substrate for the regio- and stereoselective synthesis of enamide through carbometallation reaction [19][20][21][22]. Although the stereoselectivity of the carbocupration is usually controlled through a syn

• organometallic species (i.e., copper) with a polar functional group in the vicinity of the reactive center should be able to reverse the regioselectivity of the carbometallation, as we have shown for the carbocupration of ethynyl carbamate (XR = OCONR2, Path C, Scheme 1) [24]. Herein we describe our results for

Recent advances in transition-metal-catalyzed intermolecular carbomagnesiation and carbozincation

• Kei Murakami and
• Hideki Yorimitsu

Beilstein J. Org. Chem. 2013, 9, 278–302, doi:10.3762/bjoc.9.34

• intramolecular carbomagnesiation and -zincation [15] and intermolecular carbocupration with stoichiometric copper reagents has been well established [14][18][25], catalytic intermolecular carbomagnesiation and carbozincation are still in their infancy. This article includes the advances in transition-metal

• ][51][52][53] or enolates [54] from simple alkynes by carbocupration reactions. Not only copper but also rhodium can catalyze carbometalation reactions. Hayashi applied carborhodation chemistry [55][56][57][58] to the reactions of aryl alkynyl ketones with arylzinc reagents, which provided enolates of

• (Scheme 12). Notably, the synthetic procedure is significantly versatile and various tamoxifen derivatives were also prepared in just three steps from 2g. The directing effect dramatically changed the regioselectivity in the reactions of oxygen- or nitrogen-substituted alkynes. Carbocupration of these

Intramolecular carbolithiation of N-allyl-ynamides: an efficient entry to 1,4-dihydropyridines and pyridines – application to a formal synthesis of sarizotan

• Wafa Gati,
• Mohamed M. Rammah,
• Mohamed B. Rammah and
• Gwilherm Evano

Beilstein J. Org. Chem. 2012, 8, 2214–2222, doi:10.3762/bjoc.8.250

• interest in the chemistry of ynamides [7][8][9][10][11][12][13][14][15][16][17][18] and inspired by recent reports from Meyer and Cossy [19][20][21], Marek [22][23][24] and Lam [25][26] on their carbopalladation, carbocupration and carbozincation, respectively, we decided to study the intramolecular

Highly stereocontrolled synthesis of trans-enediynes via carbocupration of fluoroalkylated diynes

• Tsutomu Konno,
• Misato Kishi and
• Takashi Ishihara

Beilstein J. Org. Chem. 2012, 8, 2207–2213, doi:10.3762/bjoc.8.249

• equiv of LHMDS in −78 °C for 1 h gave the corresponding trifluoromethylated diyne in an excellent yield. This diyne was found to be a good substrate for the carbocupration with various higher-ordered cyanocuprates to give the corresponding vinylcuprates in a highly regio- and stereoselective manner. The

• in situ generated vinylcuprates could react very smoothly with an excess amount of iodine, the vinyl iodides being obtained in high yields. Thus-obtained iodides underwent a very smooth Sonogashira cross-coupling reaction to afford various trans-enediynes in high yields. Keywords: carbocupration

• convenient and efficient access to trifluoromethylated enediynes by the highly regio- and stereoselective carbocupration reaction of trifluoromethylated diyne with various organocuprates (Scheme 1). Results and Discussion Our initial studies began with the preparation of trifluoromethylated diyne derivatives

Stereoselective synthesis of tetrasubstituted alkenes via a sequential carbocupration and a new sulfur–lithium exchange

• Andreas Unsinn,
• Cora Dunst and
• Paul Knochel

Beilstein J. Org. Chem. 2012, 8, 2202–2206, doi:10.3762/bjoc.8.248

• Andreas Unsinn Cora Dunst Paul Knochel Department Chemie, Ludwig-Maximilians-Universität München, Butenandtstr. 5-13, 81377 München, Germany 10.3762/bjoc.8.248 Abstract We have designed a new sequential carbocupration and sulfur–lithium exchange that leads stereo- and regioselectively to

• ][9]. The Normant carbocupration of terminal acetylenes allows the stereoselective preparation of trisubstituted alkenes with excellent E/Z ratio [10][11][12]. However, in order to obtain tetrasubstituted alkenes, a carbometalation of an internal alkene is required. This reaction is usually difficult

• thioether such as 1 as an activated alkyne. After a carbocupration of the alkynyl thioether 1 with the organozinc reagent 2 in the presence of CuCN·2LiCl [14], the alkenylcopper species 3 should be obtained. Stereoselective quenching with an electrophile (E1) should afford the tetrasubstituted alkenyl

Recent advances in carbocupration of α-heterosubstituted alkynes

• Ahmad Basheer and
• Ilan Marek

Beilstein J. Org. Chem. 2010, 6, No. 77, doi:10.3762/bjoc.6.77

• Ahmad Basheer Ilan Marek The Mallat Family Laboratory of Organic Chemistry, Schulich Faculty of Chemistry and the Lise Meitner-Minerva Center for Computational Quantum Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel 10.3762/bjoc.6.77 Abstract Carbocupration of α

• change the stereochemical outcome of the reaction. Representative examples are given in this mini-review. Keywords: alkynes; carbocupration; enamides; regioselectivity; stereoselectivity; syn-addition; vinylcopper; ynamides; ynol ether; Review The addition of a carbon-metal bond of an organometallic

• species to an alkyne (carbometalation reaction) is an extremely useful reaction for the preparation of polysubstituted stereodefined alkenyl metal derivatives. When the organometallic species involved is an organocopper reagent, the reaction is termed carbocupration. To be synthetically useful, the new