78349-04-9Relevant articles and documents
Photocatalytic Reductive Radical-Polar Crossover for a Base-Free Corey–Seebach Reaction
Crespi, Stefano,Donabauer, Karsten,K?nig, Burkhard,Murugesan, Kathiravan,Rozman, Ur?a
supporting information, p. 12945 - 12950 (2020/09/23)
A metal-free generation of carbanion nucleophiles is of prime importance in organic synthesis. Herein we report a photocatalytic approach to the Corey–Seebach reaction. The presented method operates under mild redox-neutral and base-free conditions giving the desired product with high functional group tolerance. The reaction is enabled by the combination of photo- and hydrogen atom transfer (HAT) catalysis. This catalytic merger allows a C?H to carbanion activation by the abstraction of a hydrogen atom followed by radical reduction. The generated nucleophilic intermediate is then capable of adding to carbonyl electrophiles. The obtained dithiane can be easily converted to the valuable α-hydroxy carbonyl in a subsequent step. The proposed reaction mechanism is supported by emission quenching, radical–radical homocoupling and deuterium labeling studies as well as by calculated redox-potentials and bond strengths.
Selectivities in the Reactions of Alkyl-, Aryl- and Heterosubstituted Organotitanium Compounds
Weidmann, Beat,Widler, Leo,Olivero, Alan G.,Maycock, Christopher D.,Seebach, Dieter
, p. 357 - 361 (2007/10/02)
Solutions of the title compounds R-Ti(OR')3 (1) are generally available from organolithium (or magnesium) derivatives according to equation 1.It is shown (table 1) that some heterosubstituted organotitanium compounds are more stable thermally than their lithium counterparts.The reagents 1 are highly selective carbonylophiles (Tables 1 and 2), their reactivity can be modified by variation of the R'O-group (Table 3) and with the chiral (S)-2-methyl-1-butoxy group an enantioselective addition can be achieved.
