Direct Synthesis of Water‐Tolerant Alkyl Indium Reagents and Their Application in Palladium‐Catalyzed Couplings with Aryl Halides

Bismuth‐Mediated Diastereoselective Allylation Reaction of Carbonyl Compounds with Cyclic Allylic Halides or Cinnamyl Halide

“…Initial studies were focused on optimization of reaction conditions by using 4-chlorobenzaldehyde (1 a) and 3-bromocyclohexene (2 a) as model substrates in the presence of bismuth powder (pre-activated by 1,2dibromoethane and TMSCl) and different additives/ catalysts in DMF at 120 8C for 12 h. As shown in Table 1, poor yield was obtained when the reaction was performed in the absence of any additive or catalyst (entry 1). Among the different additives/ catalysts (e. g., InCl 3 ,[1b,2j,10,11] PbCl 2 , [10,12] CuCl, [13] LiCl, [3b,10,14] LiI [15] ) screened (entries 2-9), LiI was found to be the optimum additive for the allylation, giving rise to the desired product 3 a in 79% NMR yield with > 99:1 dr (entry 9). In addition, it was found that the product yield gradually diminished when the reaction time was prolonged from 12 h to 48 h (entries [9][10][11], indicating that the product 3 a might not be very stable at 120 8C.…”

“…As listed in Table 4, under the optimized reaction conditions, the bismuth-mediated allylation reaction involving a wide array of aldehydes took place with high efficiency to give the anticipated homoallylic alcohols in moderate to good yields with excellent diastereoselectivity (> 99:1 dr). In addition to the high performance observed with aryl aldehydes, heteroaryl aldehydes (entries 9-10) and alkyl aldehydes (entries [12][13][14] were also proven to be suitable substrates for the reaction. Moreover, the allylation reaction occurred selectively at the formyl group of a, bunsaturated aldehyde 1 l, rather than proceeding at the CÀC double bond via a Michael-type reaction pathway (entry 11).…”

Synthesis of Acyl Alkenylindium Reagents and Their Application in the Synthesis of (Z)-α,β-Unsaturated Ketones via Palladium-Catalyzed Cross-Coupling Reaction

“…Among them, because organoindium reagents showed advantageous properties related to their selectivity and reactivity, ease of handling and preparation, thermal stability, and low toxicity, cross-coupling reactions using organoindium reagents have also been of great interest. After Pd-catalyzed cross-coupling reactions using tri­(organo)­indium reagents were reported by Sarandeses and co-workers, coupling reactions using a large number of organoindium reagents such as allylindiums, allenylindiums, alkenylindiums, 1,3-butadien-2-ylindiums, tri­(naphthyl)­indiums, tetra­(organo)­indates, indium tri­(organothiolates), acylindiums, β-phosphoryl alkylindiums, arylindiums, benzylindiums, and alkylindiums have been demonstrated . Recently, Loh and co-workers reported the synthetic method of indium homoenolates via oxidative addition of indium and indium trichloride to α,β-enones and insertion of indium into a β-halo ester .…”

Cesium carbonate‐catalyzed indium insertion into alkyl iodides and their synthetic utilities in cross‐coupling reactions

“…mild reactivities, good functional group tolerance, and good chemo‐ and stereo‐selectivities) as compared with other more reactive organometallic compounds, and their capabilities to participate in a wide variety of organic transformations . Generally, organoindium reagents could be synthesized by means of the transmetallation of more reactive organometallic reagents with indium (III) salt or via the direct indium insertion into organohalides . However, the direct insertion of indium into some unactivated organohalides normally could not take place with the sole use of indium metal in the absence of any additive or catalyst.…”

“…However, the direct insertion of indium into some unactivated organohalides normally could not take place with the sole use of indium metal in the absence of any additive or catalyst. With regard to relatively less reactive organic halides, such as aryl halides, alkenyl halides, benzyl halides and alkyl halides, the insertion reactions usually should be conducted in the co‐existence of stoichiometric amounts of additives (such as LiX[5,6,7a,8c,d,10] or CuX[8a–c]). Recent advancements from our lab have shown that a catalytic amount of indium (III) chloride or iodine was also able to catalyze the direct insertion of metallic indium into alkyl halides .…”