(4R,5R)-2-Bromo-1,3-bis[(4-methylphenyl)sulfonyl]-4,5-diphenyl-1,3,2-diazaborolidine

A Bidirectional SE′ Strategy for 1,5-syn and 1,5-anti Stereocontrol toward the Synthesis of Complex Polyols

“…These efforts have been applied for a stereocontrolled synthesis of the C(1)–C(9) fragment of peloruside A ( 5 ) as shown in Scheme . Thus, facile transmetalation of allylic stannane 6 using the bromoborane 7 provided in situ generation of nonracemic 1,3,2-diazaborolidine 8 upon stirring at 22 °C for 16 h. The ( R , R )-1,2-diamino-1,2-diphenylethylene N , N -sulfonamide was incorporated as an effective chiral controller . A rapid S E ′ reaction was observed upon cooling to −78 °C with the addition of nonracemic aldehyde 9 (1.0 equiv) and 2,6-di- tert -butyl-4-methylpyridine (1.1 equiv) leading to stereoselective production of homoallylic alcohol 10 (80%).…”