Institute of Organic Chemistry , Faculty of Chemistry and Pharmacy , University of Regensburg , Universitätsstraße 31 , 93053 Regensburg , Germany . Email: [Email]
We present a redox-neutral method for the photocatalytic generation of carbanions. Benzylic carboxylates are photooxidized by single electron transfer; immediate CO2 extrusion and reduction of the in situ formed radical yields a carbanion capable of reacting with aliphatic aldehydes as electrophiles giving the Grignard analogous reaction product.