One-pot synthesis of protected prostaglandins from alkynes and cyclopentenones. In situ generation of higher order cyanocuprates derived from alkenylzirconium intermediates

Transmetalation Reactions Producing Organocopper Reagents

“…Formation of an intermediate zincate prior to transmetalation to the copper species facilitates the Michael addition (Scheme 2.62) [135]. This methodology has been applied to the preparation of protected misoprostol 129 (Scheme 2.63) [136,137].…”

“…Remarkably, a variety of primary and secondary alkylzirconium complexes can be added to enones in 1,4-fashion under mild conditions [134,138]. Interestingly, treatment of zirconocyclopentadienes such as 130 with alkynes such as dimethyl acetylenedicarboxylate in the presence of CuCl gives benzene derivatives such as 131 [136,137]. A transmetalation from Zr to Cu has been postulated in this reaction.…”

Catalytic Enantioselective Addition of Alkylzirconium Reagents to Aliphatic Aldehydes

“…Organozirconium reagents [ 33 , 34 , 35 ] are relatively inert toward carbonyl compounds [ 36 ], but their nucleophilic character can be enabled by different catalysts or stoichiometric mediators [ 37 , 38 , 39 , 40 , 41 , 42 ]. Thus, the addition of organozirconium reagents to aldehydes [ 43 , 44 , 45 , 46 , 47 , 48 , 49 ], ketones [ 50 , 51 ], enones [ 52 , 53 , 54 ], epoxides [ 55 ] and isocyanates [ 56 ] is possible in the presence of Ag(I), ZnBr 2 or Me 2 Zn; although these protocols are rarely enantioselective [ 57 , 58 , 59 , 60 , 61 , 62 , 63 ].…”

Catalytic Enantioselective Addition of Organozirconium Reagents to Aldehydes

“…The use of less reactive nucleophiles circumvents some of these issues. Organozirconium reagents [ 42 , 43 , 44 , 45 , 46 , 47 , 48 ] are relatively inert toward carbonyl compounds [ 49 ], but the use of catalysts or a stoichiometric mediator [ 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 ] enables the nucleophilic attack and subsequent carbon-carbon bond formation. Thus, in the presence of Ag(I), ZnBr 2 , or Me 2 Zn, organozirconium reagents can readily be added to aldehydes [ 61 , 62 , 63 , 64 , 65 , 66 , 67 , 68 ], ketones [ 69 , 70 ], and also enones [ 71 , 72 , 73 , 74 ], epoxides [ 75 ], and isocyanates [ 76 ], although enantioselective protocols have been rare so far [ 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 , 86 , 87 , 88 , 89 , 90 ,…”