Catalytic Enantioselective Synthesis of Functionalized Cyclopropanes from α‐Substituted Allyl Sulfones with Donor‐Acceptor or Diacceptor Diazo Reagents

Abstract

The catalytic asymmetric synthesis of highly functionalized cyclopropanes from α-substituted allyl sulfones and silanes is reported. The reaction, using α-aryl diazoacetates or diacceptor diazo reagents, catalyzed by a chiral rhodium complex (Rh 2 ((S)-BTPCP) 4 ), furnished the corresponding cyclopropanes in moderate to high yields (27-97 %), high diastereoselectivities (68 : 32 to 20 : 1 d.r.) and moderate to excellent ee (40-99 %). This methodology offers a privileged access to an underexplored class of enantioenriched cyclopropanes with a high level of functionality, an asset for further post-functionalization and their incorporation into more complex structure.

Chemoenzymatic synthesis of optically active α-cyclopropyl-pyruvates and cyclobutenoates via enzyme-catalyzed carbene transfer with diazopyruvate

“…As part of our ongoing program dedicated to the development of straightforward access to functionalized cyclopropanes, 25 here we report the first example of biocatalytic enantioselective cyclopropanation using ethyl diazopyruvate (EDPv) as a new biocatalyst-compatible carbene source. The resulting α-cyclopropylpyruvates can be produced with high enantioselectivity (up to >99% ee).…”