Synthesis and reactions of terpenyl diselenides functionalized with phenyl and naphthyl groups

An efficient methodology for the synthesis of chiral terpenyl diselenides functionalized with phenyl and naphthyl groups has been developed. Using the reaction of sodium diselenide with terpenyl tosylates and chlorides, the corresponding diselenides derived from 8-phenyl menthol and isopinocampheol modified at the 10-position were obtained. Diselenides were transformed into electrophilic selenium reagents and tested in the asymmetric selenenylation of styrene. The effect of aryl groups on the enantioselectivity of the addition reaction was examined.

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(1R,2S,5R)-(+)-Bis(8-phenyl menthyl)diselenideC32H46Se2Ee >99%[α]D20 = −44.4 (2.25, CHCl3)Source of chirality: (−)-mentholAbsolute configuration: (1R,2S,5R)

(1S,2S,5R)-(−)-Bis(8-phenyl neomenthyl)diselenideC32H46Se2Ee >99%[α]D20 = +246.4 (c 1.65, CHCl3)Source of chirality: (−)-mentholAbsolute configuration: (1S,2S,5R)

(1R,2S,3S,5R)-(+)-Bis(10-phenyl pinocamphyl)diselenideC32H42Se2Ee >95%[α]D20 = +49.5 (c 1.84, CHCl3)Source of chirality: (−)-myrtenolAbsolute configuration: (1R,2S,3S,5R)

(1S,2S,3S,5R)-(+)-Bis(10-phenyl isopinocamphyl)diselenideC32H42Se2Ee >95%[α]D20 = +32.3 (c 2.06, CHCl3)Source of chirality: (−)-myrtenolAbsolute configuration: (1S,2S,3S,5R)

(1R,2S,3S,5R)-(+)-Bis(10-(1-naphthyl)pinocamphyl)diselenideC40H46Se2Ee >95%[α]D20 = +4.0 (c 2.58, CHCl3)Source of chirality: (−)-myrtenolAbsolute configuration: (1R,2S,3S,5R)

(1S,2S,3S,5R)-(+)-Bis(10-(1-naphthyl)isopinocamphyl)diselenideC40H46Se2Ee >95%[α]D20 = +98.05 (c 0.74, CHCl3)Source of chirality: (−)-myrtenolAbsolute configuration: (1S,2S,3S,5R)

(1S,2R,4S)-(+)-Bis(2-apopinanyl)diselenideC18H30Se2Ee >92%α]D20 = +250.9 (c 2.96, CHCl3)Source of chirality: (−)-β-pineneAbsolute configuration: (1S,2R,4S)

(1R,2R,3S,5R)-(+)-Bis(2-phenyl apopinocamphyl)diselenideC30H38Se2Ee >92%[α]D20 = +101.75 (c 2.86, CHCl3)Source of chirality: (−)-β-pineneAbsolute configuration: (1R,2R,3S,5R)