Asymmetric Addition of Organolithium Reagents to Prochiral Arene Tricarbonylchromium Complexes

Functionalized 1,2‐Dihydronaphthalenes from the Cu(OTf)2‐Catalyzed [4+2] Cycloaddition of o‐Alkynyl(oxo)benzenes with Alkenes

“…The resulting mixture was stirred at 80 8C for 10 h and then cooled to room temperature. A saturated aqueous solution of NH 4 Cl was added, and the mixture was extracted with ether three times. The combined extracts were washed with brine, dried over MgSO 4 , and concentrated to dryness to leave the crude product, which was purified by silica gel column chromatography using hexane/EtOAc (8:1) as the eluent to give 3 a (149 mg, 0.48 mmol) in 96 % yield.…”

Enantioselective Synthesis with Lithium/(−)‐Sparteine Carbanion Pairs

“…B. Kaiser thus investigated the ( -)-sparteine-induced deprotonation of S-alkyl thiocarbamates of the type 224;[235* 2361 the reactions with S-butyl esters (Scheme 83) will be discussed as 21 6 Scheme 80. Diastereo-and enantioselective reaction of the tricarbonylchromium arene complex 214 [226]. HMPA = hexamethylphosphoramide.…”

Bidirectional Metalation of Hydrobenzoin: Direct Access to New Chiral Ligands and Auxiliaries

“…27 In this work, the four ligands 102-105, were screened in reactions with phenyllithium, vinyllithium, methylllithium and n-BuLi and it was found that the dimethoxyhydrobenzoin 105 imparted the highest degree of enantioselectivity for this reaction (phenyllithium e.r. = 28:1; vinyllithium and methyllithium, e.r.…”