Reaction yielded inferior was examined that this bisvinylogous Mukaiyama aldol reaction
Reaction yielded inferior was examined that this bisvinylogous Mukaiyama aldol reaction yieldedbut still bears possible for future investinylogous version under the same situations, but itit nonetheless bears potential for future investinylogous version below precisely the same conditions, inferior final results than its frequent vinylogous version (��)-Indoxacarb Protocol gations. gations. beneath the exact same conditions, but it still bears prospective for future investigations.O O R1 R1 H HOTBS OTBS OR3 OR27 (5 mol ) 27 (5 mol ) Et2O, -78 , 72 Et2O, -78 , 72 h h as much as 75 yield up to 75 yieldOTBS OTBS R1 R1 R2 ROO+ +OR3 OR5 five (1.five eq.) (1.five eq.) OTBS OTBSR2 R2829 29 up 90 ee up toto 90 ee OTBS OTBSOOO O OMe OMeFFOTBS OTBSOOOMe OMe37 yield, 62 ee 37 yield, 62 ee / == 1.two:1 / 1.two:OMe OMe47 yield, 8 eeee 47 yield, eight / = three.two:1 / = three.two:75 yield, 90 ee 75 yield, 90 ee / = 5:1 / = five:Scheme 9. First organocatalyzed enantioselective bis-vinylogous Mukaiyama aldol reaction. Scheme 9. Very first organocatalyzed enantioselective bis-vinylogous Mukaiyama aldol reaction.Additionally, List al. also investigated the the closely connected alkynylogous MukaiFurthermore, List etet al. also investigated the closely associated alkynylogous Mukai-alFurthermore, List et al. also investigated closely related alkynylogous Mukaiyama dol reaction in between silyl alkynyl ketene Boc-Cystamine Biological Activity acetals 30 and various and various aldehydes[38]. yama aldol reaction in between silyl alkynyl ketene acetals 30 aldehydes 5 (Scheme ten) 5 five aldol reaction involving silyl alkynyl ketene acetals 30 and distinctive aldehydes They employed They employed the disulfonimide disulfonimide catalyst class 31 to (Scheme 10) [38]. the earlier displayedearlierdisplayed catalyst class 31catalyst class tetra(Scheme 10) [38]. They employed the earlier displayed disulfonimide to produce 31 to substituted allenes 32 with superb with great yields (as much as 92 ), diastereoselectivigenerate tetra-substituted allenes 32 with great 92 ), diastereoselectivities (as much as 27:1), generate tetra-substituted allenes 32 yields (up to yields (as much as 92 ), diastereoselectiviand enantioselectivities (up to 97 ee). ties (up to 27:1), and enantioselectivities (as much as 97 ee). ties (as much as 27:1), and enantioselectivities (up to 97 ee).O O R11 R 5 5 CO2Et CO2Et Me Me Np Np OH OH CO2Et CO2Et Me Me H H R3 three R + + R22 R 30 30 OTBS OTBS 1) 31 (5(five mol ) 1) 31 mol ) Et2O, 0 0 , 24-120 h Et O, , 24-120 hOH OH R1 1 RCO2Et Et CO2 R3ROEt OEt2) HCl inin MeOH two) HCl MeOH up to 92 yield as much as 92 yield up to 27:1 d.r. up to 27:1 d.r. Np = naphthyl Np = naphthyl OH OH Np Np CO2Et CO2Et nBu nBuR2 2 R 32 32 as much as 97 ee up to 97 eeMe MeOH OH Me MeMe Me 78 yield, 27:1 d.r. 78 yield,ee d.r. 92 27:1 92 eeMe Me 85 yield, 19:1 d.r. 85 96 ee yield, 19:1 d.r. 96 eeMe Me 68 yield, 20:1 d.r. 68 97 ee yield, 20:1 d.r. 97 eeF3 C F3 C Ar Ar OO O S O S NH NH S S O O O Ar O Ar Ar = 31 Ar =CF3 CF3 CF3 CFCF3 CFScheme 10. Initial enantioselective alkynylogous Mukaiyama aldol reaction organocatalyzed by diScheme ten. Very first enantioselective alkynylogous Mukaiyama aldol reaction organocatalyzed by Scheme ten. Initial enantioselective alkynylogous Mukaiyama aldol reaction organocatalyzed by disulfonimides presented by by List al. al. [38]. disulfonimides presented List et al.[38]. sulfonimides presented by List et et [38].Extra not too long ago, the group Alem investigated the the organocatalyzed VMAR Far more not too long ago, the group of of Alem investigated organocatalyzed VMAR of isa-of Much more lately, the grou.
