Synthesis of optically active gem-difluorocyclopropanes through a chemo-enzymatic reaction strategy

Chemo-Enzymatic Synthesis of a Multi-Useful Chiral Building Block Molecule for the Synthesis of Medicinal Compounds

“…The absolute configuration of ( R )- 1 was confirmed by comparison with the sign of specific rotation value of ( R )-2-amino-2-methyl-4-(4-(heptyloxy)phenyl)butan-1-ol ( 5 ) [21,22] ([α] D −14.4 (c 0.03, CHCl 3 ), lit [21] −14.0 (CHCl 3 )) which was derived from our compound ( R )- 1 (96% ee ). The results agree with the established enantio-favoritism of lipase QL-catalyzed transesterification [23]. …”

Recent advances in the syntheses, transformations and applications of 1,1-dihalocyclopropanes

“…104 A mixture of meso and racemic bis(gem-difluorocyclopropylmethanol) tethered by a phenyl spacer was resolved by vinylation in the presence of Lipase SL-25. 104 A mixture of meso and racemic bis(gem-difluorocyclopropylmethanol) tethered by a phenyl spacer was resolved by vinylation in the presence of Lipase SL-25.…”

“…Itoh et al also reported a chemo-enzymatic strategy for the generation of trans,trans-bis-gem-difluorocyclopropane 204 (Scheme 71). 104 Scheme 66 Stereoselective carbonylation of dihalocyclopropane using CO and Bu 3 SnH/Bu 3 Sn(CH 2 CHvCH 2 ). A mixture of meso and racemic bis(gem-difluorocyclopropylmethanol) tethered by a phenyl spacer was resolved by vinylation in the presence of Lipase SL-25.…”

gem-Difluorocyclopropane as core molecule candidate for liquid crystal compounds

“…2.73 (2H,dd,J = 14.2,7.3 Hz),4.01 (4H,t,J = 6.4 Hz),m),m),6.91 (4H,d,J = 9.2 Hz),7.20 (4H,s),7.99 (4H,d,J = 8.71 Hz); 13 C NMR (125 MHz,CDCl 3 ) d 14.0,22.6,25.9,28.3 (t,29.2 (t,31.5 (t,31.7,60.8,68.2,113.0 (t,114.1,121.7,128.3,131.7,132.0,163.2,166.1;19 F NMR (470 MHz,CDCl 3 ) d 25.6 (ddd,J = 587,155,17.3 Hz); IR (KBr, cm À1 ); 3854, 3651, 2924, 2849, 1707, 1609, 1514, 1254, 1105, 1009. ½a 24 D þ 19:4 (c 1.0, CHCl 3 ); Anal. Calcd for C 44 H 54 F 4 O 6 ;C,70.01;H,7.21.…”