112018-78-7

Upstream product

• 23202-10-0 (Z)-cyclooct-2-enone 
• 4925-71-7 cis-1,2-epoxycyclooctane 
• 286-62-4 Cyclooctene oxide 
• 7422-06-2 (Z)-3-bromocyclooct-1-ene 
• 931-88-4 cis-Cyclooctene 

Relevant academic research and scientific papers

Guanidine–Copper Complex Catalyzed Allylic Borylation for the Enantioconvergent Synthesis of Tertiary Cyclic Allylboronates

An enantioconvergent synthesis of chiral cyclic allylboronates from racemic allylic bromides was achieved by using a guanidine–copper catalyst. The allylboronates were obtained with high γ/α regioselectivities (up to 99:1) and enantioselectivities (up to 99 % ee), and could be further transformed into diverse functionalized allylic compounds without erosion of optical purity. Experimental and DFT mechanistic studies support an SN2′ borylation process catalyzed by a monodentate guanidine–copper(I) complex that proceeds through a special direct enantioconvergent transformation mechanism.

Allylic alcohols via catalytic asymmetric epoxide rearrangement

Epoxides using chiral lithium amides, but other than for a small subset of meso-epoxides, insufficient reactivity and enantioselectivity hamper the existing methods. Furthermore, the chiral reagents are often required in large excess. This study presents a general and highly enantioselective process that, in addition, is based on catalytic amounts (5 mol %) of enantiopure (1S,3R,4R)-3-(1-pyrrolidinyl)methyl-2-azabicyclo[2.2.1]heptane and lithium diisopropylamide as the stoichiometric base. The influence of structural modification of the catalyst is studied in terms of activity, enantioselectivity, and aggregation behavior. The utility of the process is demonstrated by its application to a variety of epoxide derivatives (≥94% ee for 11 out of 14 examples), including the formal syntheses of, e.g., a prostaglandin core unit, epibatidine, carbovir, faranal, and lasiol. The system is readily extended to the resolution of racemic epoxides, which allows access to highly enantioenriched epoxides or allylic alcohols, even at conversions near 50%.

Catalytic enantioselective deprotonation of meso-epoxides utilising homochiral bis-lithium amide bases

(R)-2-Cyclohexen-1 ol and (R)-2-cyclooctene-1-ol have been prepared in very good ee using R,R-homochiral bis-lithium amide bases derived from homochiral C2 symmetric diamines. (R)-2-Cyclohexen-1-ol has been synthesized in good ee utilising catalytic homochiral bis-lithium amide in the presence of n-butyl lithium.

A novel highly effective chiral lithium amide for catalytic enantioselective deprotonation of meso-epoxides

A highly enantioselective deprotonation of meso-epoxides was achieved by a catalytic amount of a new chiral lithium amide, derived from (2S,3aS,7aS)-2-(pyrrolidin-1-ylmethyl)octahydroindole, in the presence of excess lithium diisopropylamide to afford the corresponding allylic alcohol derivatives up to 94% ee.