Copper-CatalyzedN-Alkynylations of Sulfoximines with Bromoacetylenes

Abstract

N-Alkynylated sulfoximines have been obtained by copper-catalyzed cross-coupling reactions starting from NH-sulfoximines and bromoacetylenes in moderate to good yields. The reaction conditions are mild, and the substrate scope is wide.

Stereoselective Synthesis of Trisubstituted Alkenes through Sequential Iron‐Catalyzed Reductive anti‐Carbozincation of Terminal Alkynes and Base‐Metal‐Catalyzed Negishi Cross‐Coupling

“…20 A 1 L round-bottom flask equipped with a Teflon-coated magnetic stir bar was charged with triphenylphosphine (3 equiv) and dichloromethane (~300 mL). Tetrabromomethane (1.5 equiv) was then added slowly into the reaction mixture, and the reaction mixture was stirred at room temperature until most of the solids dissolved.…”

“…Without a Ni catalyst, only a low yield of was obtained (Table S2, entry 16). Nickel(II) precatalysts, Ni II (TMEDA)(o-tolyl)(Cl) 37 and Ni II Br 2 (diglyme), did not efficiently catalyze the reaction as compared to Ni(cod) 2 despite the use of other derivatives of 2,2'-dipyridiyl ligands (Table S2, entries [17][18][19][20][21]. The conditions in entry 14 were used as the optimal general conditions for substrate scope study of aryl halides and other sp 2 -carbon halogen bonds.…”

Palladium‐Catalyzed Regioselective Synthesis of 3‐(Hetero)Arylpropynamides from gem‐Dibromoalkenes and Isocyanides

“…FT-IR (KBr): 3263,3050,2926,2851,2212,1626,1584,1446,1247,1137,803,746 1, 149.4, 146.8, 144.7, 133.1, 128.74. 128.72, 128.4, 126.4, 115.1, 90.0, 78.4, 48.9, 33.8, 32.5, 25.6, 25 ,69.12;H,5.48;N,8.96%;Found;C,68.99;H,5.54;N,9.05%.…”

“…1,1-Dibromo-1-alkenes, which are easily derived from aldehydes or ketones with CBr 4 /PPh 3 , are extremely versatile precursors and are often used for synthesizing diverse molecules. [5] Applications of these building block molecules have been extended to the generation of acetylene derivatives, including alkynylphosphonates, [6] ynol ethers, [7] symmetric and asymmetric 1,3-diynes, [8] ynamides, [9] 1,2-diarylacetylenes, [10] ynoate esters, [11] and ynsilanes. [12] Piguel et al proposed a method for copper-catalyzed, C 2 -directed alkynylation of 3H-imidazo [4,5-b]pyridine derivatives using 1,1-dibromo-1-alkenes.…”

Total Synthesis of Dictyodendrins by the Gold‐Catalyzed Cascade Cyclization of Conjugated Diynes with Pyrroles

“…[5] Thesubsequent Sonogashira coupling of 19 with trimethylsilylacetylene,followed by desilylation of the coupling product with K 2 CO 3 and methanol, afforded the corresponding terminal alkyne 16 b in quantitative yield. [14] Cadiot-Chodkiewicz coupling [13a] between 16 b and bromoalkyne 17 b [15] afforded the corresponding conjugated diyne 21.T reatment with TMSOTf and 2,6-lutidine [16] led to selective removal of the Boc protecting group,a nd the resulting aniline 22 was then treated with tBuONO and TMSN 3 to give the corresponding azido alkyne 10 d in 87 % yield over three steps from 16 b. [17] Several other conjugated diynes were prepared either in asimilar manner (for 10 a)or by the derivatization of the conjugated diyne 21 (for 10 b,c; see the Supporting information).…”