Catalytic Enantioselective Hydrostannation of Cyclopropenes
摘要:
The first examples of catalytic enantioselective hydrostannation of the C=C double bond of cyclopropenes has been demonstrated. This method allows for the efficient synthesis of 2,2-disubstituted cyclopropylstannanes with high degrees of diastereo- and enantioselectivity. The facial selectivity of this reaction is entirely controlled by steric factors. A variety of functional groups at C-3 of the cyclopropenes were tolerated.
Cobalt‐Catalyzed Diastereo‐ and Enantioselective Hydroalkylation of Cyclopropenes with Cobalt Homoenolates
作者:Wei Huang、Fanke Meng
DOI:10.1002/anie.202012122
日期:2021.2
in situ from ring‐opening of easily accessible cyclopropanols promoted by a chiral phosphine–cobalt complex is presented. Such a process represents the unprecedented and direct introduction of a wide range of functionalized alkylgroups without the need of pre‐formation of stoichiometric amounts of organometallic reagents onto the cyclopropane motif, affording multi‐substituted cyclopropanes in up to 99 %
A full account on rhodium‐catalyzed asymmetric, directed hydroboration of functionalized prochiral cyclopropenes affording enantiomerically enriched cyclopropylboronates is reported. The scope and limitations of two alternate directing groups, ester and carboxamide, are evaluated. It was found that hydroboration of esters appeared to be more sensitive to substitution in the aromatic ring of the substrates
Rhodium-Catalyzed Hydroformylation of Cyclopropenes
作者:William M. Sherrill、Michael Rubin
DOI:10.1021/ja805059f
日期:2008.10.15
The first catalytic diastereo- and enantioselective hydroformylation of cyclopropenes was demonstrated. The reaction proceeds efficiently under very mild conditions and low catalyst loadings providing high yields of cyclopropylcarboxaldehydes. This novel methodology represents a convenient, atom-economic approach toward optically active cyclopropylcarboxaldehydes from readily available prochiral cyclopropenes.