Synthesis of glucoside-based imidazolium salts for Pd-catalyzed cross-coupling reaction in water

Synthesis of 2,7-Diaryl Substituted Fluorenes and Fluorenones

“…28 [43,60,[62][63][64] F F 29 [43,60,[62][63][64] F F F 31 [60,64] N Ph Ph 32 [43,60,62] N Ph 33 [59] H N O t Bu O 30 [55] F C 5 H 11 F 25 [55] C 6 H 13 34 [64] COOEt 35 [12] NH 2 36 [12] Ar Ar R R Ar = 54 R = Me [82] 55 R = Et [13] 56 R = C 4 H 9 [41] 57 R = C 6 H 13 [90] 58 R = C 8 H 17 [46,91] 59 R = cyclopropane [95] 60 R = cyclopentane [45] 61 R = cycloheptatrienylidene [94] 62 R = benzylidene [20] CN 52 R = cyclopentane [45] 53 R = C 8 H 17 [46] 81 R = C 4 H 9 [61] 82 R = Et [13] 83 R = cyclopropane [95] 84 R = cycloheptatrienylidene [94] 90 R = Et [96,98] 91 R = cyclopropane [95] 92 R = 4-NO 2 -C 6 H 4 [81] R = cyclopropane [95] 101 87 R = Me [82] 88 R = cyclopropane [95] 89 R = 3-(9-phenylcarbazoyl) [93] F OMe 78 R = Me [82] 79 R = Ph…”

“…93 R = Et [96] 94 R = C 4 H 9 [44,[61][62] R = Me [97] 86 R = CH 2 COOEt [59] 99 NHBoc F F 47 R = Et [61] 48 R = C 6 H 13 [62][63] R = Et [61] 102 S 74 R = Me [55] 75 R = Et [55] C 5 H 11 R = Et [98] 98 [98] 97 [19] 77 N 65 R = Et [43] 66 R = C 4 H 9 [44] 67 R = C 6 H 13 [43] 68 R = C 8 H 17 [43] R = cyclopropane [95] 107 化下的芳基-芳基交叉偶联反应为例, 在乙醚中回流 1.5 h 后 2,7-二苯基芴的气相色谱收率约为 90% [26] . 由于卤 代芳烃反应活性依照 ArI、 ArBr 和 ArCl 的顺序降低, 将 底物替换为 2,7-二溴芴后 2,7-二苯基芴的气相色谱收率 降低至 73%.…”

“…此外, 他们使用 Glu 结构结合长链烷基 NHC 合成了直径 1.7～2.1 nm 的高分 散性水溶 Pd 纳米粒子, 并用于催化 24、27、28 和 29 的合成, 以叔丁醇钾为碱, 得到 94%～96%收率时 M10 的用量仅需 0.0001 mol%即可, 反应时间也仅需 0.1 h [62] . M11 中含有的氧原子可能在反应中参与配位, 从而影响 反应活性, 化合物 24、28 和 29 的合成可在纯水中完成, 收率为 93%～97%, 但是 M11 的用量需要增加至 1.5 mol% [63] . M12 在 NHC 结构中引入苯环也可实现增加活 性中心空间位阻的作用, 0.03 mol%用量即可催化多种 37 (44), 38 (20), 39 (16), 40 (28), 41 (7), 42 (18), 43 (7), 44 a Isolated yield unless otherwise noted.…”

“…虽 然这些 Suzuki-Miyaura 交叉偶联反应实现了许多 9-取 代-2,7-二芳基芴的制备, 但仍然存在一些问题: (1)反应 时间过长, 通常需要回流 1 d, 有一些反应甚至需要回 流 3 d, 能耗过高 [24,90] ; (2)双偶联产物收率不高, 且不同 产物间收率差别大(38%～85%) [55,[91][92] ; (3) Pd 催化剂用 量过高, M2 一般用量为 2～5 mol%, 甚至有报道高达 10～20 mol%, 导致合成和分离成本过高 [1,20,82,93] . 使用 含有 Glu 结构的 NHC/Pd 催化体系 M9～M12 和 M14 可使这些问题得到改善 [43,44,[61][62][63] a Isolated yield unless otherwise noted. GC＝GC yield.…”

Carbohydrate-based N-heterocyclic carbene-metal complexes: a new avenue for sustainable catalysts in organic transformations

“…[20][21][22][23][24][25] Pioneering work involving carbohydrate incorporation into phosphine and phosphate ligands has been well established. [26][27][28][29][30][31] Furthermore, carbohydrates incorporated with NHC ligands have been recently developed. The incorporation of these physiologically active residues into the skeleton of NHC-metal complexes may reduce toxicity while increasing biocompatibility and solubility.…”