recisely Designed Catalysts ews Letter Vol. 5 May, 2016
E-mail: sawamura@sci.hokudai.ac.jp Silica-SMA Silica-TI S-T Figure 1 Si 3 Si Si Si Si 2 Silica-SMA Si 3 Si Si Si Si 2 Silica-TI t Bu S S S-T t Bu S t Bu Figure 1. Structures of Silica-SMA, Silica-TI and S-T Silica-SMA-Ir C Silica-SMA Ir C Scheme 1 1 γ C C 2 C 1,3-3 Scheme 1. Silica-SMA-Ir-catalyzed C borylation of Alkyl Side Chains of eteroarenes et (2 3 equiv) B B [Ir()(cod)] 2 (2 mol% Ir) Silica-SMA (2 mol%) or TF, 12 15 h et 60 C, 83% 60 C, 72% 50 C, 91% 50 C, 99% S 60 C, 80% 80 C, 72%
Silica-TI d Silica-TI M Scheme 2Silica-TI d 4 Scheme 2. Synthesis of Silica-TI (left) and Its Application to the d-catalyzed Suzuki Miyaura Cross-Coupling of Aryl Chlorides (right) Si silica gel imidazole toluene 100 C, 16 h 3 Siimidazole TF 60 C, 24 h Silica-TI () 2 B h (1.2 equiv) d(ac) 2 (0.5 mol%) Silica-TI (0.6 mol%) K 3 4 (3 equiv) TF, 60 C, 12 h 93% h S-DBz i 1,2-() S-DBz i - 1,3- C /C Scheme 3 5 Scheme 3. The S-DBz-i Catalyst Systems for the Amination of Aryl Chlorides with -Alkyl rimary Amines (top) and for the C /C Coupling between 1,3-Azoles and Aryl ivalates (bottom) i(cod) 2 (1 mol%) S-DBz (1.5 mol%) 2 nc8 nc8 17 17 (1.5 equiv) a (1.5 equiv) toluene 120 C, 24 h 92% (with BIA, 0%) S S S S (1.5 equiv) i(cod) 2 (5 mol%) S-DBz (6 mol%) Cs 2 C 3 (1.5 equiv) m-xylene 150 C, 24 h 85% (with DCYE, 3%) S-DBz Cy 2 Cy 2 DCYE (1) Kawamorita, S.; Murakami,.; Iwai, T.; Sawamura, M. J. Am. Chem. Soc. 2013, 135, 2947. (2) Murakami,.; Tsunoda, K.; Iwai, T.; Sawamura, M. Chem. Eur. J. 2014, 20, 13127. (3) Murakami,.; Iwai, T.; Sawamura, M. Synlett 2016, 27, 1187. (4) Iwai, T.; Konishi, S.; Miyazaki, T.; Kawamorita, S.; Yokokawa,.; hmiya,.; Sawamura, M. ACS Catal. 2015, 5, 7254. (5) 2015-046761
E-mail: ishihara@cc.nagoya-u.ac.jp BIL 1 Brønsted 1 Lewis Lewis Brønsted (LBA)Lewis 1 3 Lewis 1 1 α- DA BBr 3 1 (Scheme 1) Diels Alder 1,2- DA 1,2- BBr 3 1 MacMillan α- 1 C Ar endo:exo = 2:98 99%, 89% ee (exo) Ar Lewis base!! Lewis acid! BBr 3 Brønsted acid C endo:exo = 5:95 75%, 90% ee (exo) Br C endo:exo = 94:6 99% 91% ee (endo) Scheme 1. BBr 3 1-catalyzed Enantioselective Diels Alder eaction C 2 h Br! Ar B Br! Br! 3! Ar! C endo:exo = 94:6 88% 94% ee (endo) 4-hC 6 4 BBr 3 h 2 C 4-hC 6 4 (10 mol%) n MX 3 = BBr 3 C C MS 5Å, C 2 2 endo:exo = >99:1 78 ºC, 3 h 82%, 95% ee (endo) Scheme 2. Enantioselective Diels Alder eaction of 1,2-Dihydropyridines
BBr 3 1 α- 1,2- DA (Scheme 2) DA ()- 2 (Scheme 3)DA S 2 ()-2 DA ()-2 α- DA 1 3 BBr 3 3 DA (Scheme 4) LBA 1 3 Lewis - DA 1 α- DA α- 1,2- (1) atano, M.; Goto, Y.; Izumiseki, A.; Akakura, M.; Ishihara, K. J. Am. Chem. Soc. 2015, 137, 13472. (2) atano, M.; Ishihara,.; Goto, Y.; Ishihara, K. Synlett 2016, 27, 564 (uster reface: BIL hosphates for Chemistry by T. Akiyama) h 2 C C 92% ee (endo) (3) atano, M.; ayashi, K.; Sakamoto, T.; Makino, Y.; Ishihara, K. Synlett 2016, 27, 1061 (uster reface: on-covalent Interactions in Asymmetric Catalysis by. J. hipps) Br 1) ab 4 TF/ 2 rt, 1 h 2) a aq. dioxane rt, 3 h 1) (TMSC 2 ) 2 TMSTf, C 2 2 C 2 20 C, 12 h 2) a, reflux, 16 h 97% (2 steps) G 91% (2 steps) Scheme 3. Formal Asymmetric Synthesis of ()-2 F 3 C C 2 3 1) 2) BBr 3 Tf 3 aq. rt, 9 h 2,6-(i-r) 2-4-h-C 6 2 2,6-(i-r) 2-4-h-C 6 2 (10 mol%) ai 4 a 2 4 2, rt, 15 h G 77% (2 steps) C 2 Et ()-2 CF 3 C 2 MS 5Å, C 2 2 endo:exo = 86:14 78 ºC, 5 h >99%, 93% ee (endo) Scheme 4. Enantioselective DA eaction of!-trifluoromethylacrylates