Rhodium-catalyzed asymmetric 1,6-addition of aryltitanates to enynones giving axially chiral allenes

[GRAPHICS] The addition of aryltitanate reagents ArTi(OPr-i)(4)Li to 3-alkynyl-2-en-1-ones in the presence of chlorotrimethylsilane and a rhodium-(R)-segphos as a catalyst proceeded in a 1,6-fashion to give a high yield of axially chiral allenylalkenyl silyl enol ethers with up to 93% ee.