Disclosed are compounds of Formula 1, including all stereoisomers, N-oxides, and salts thereof: wherein R1, R2, R3, R4, R5, R6, Q1, Q2, Y1, and Y2 are as defined in the disclosure. Also disclosed are compositions containing the compounds of Formula 1 and methods for controlling undesired vegetation comprising contacting the undesired vegetation or its environment with an effective amount of a compound or a composition of the invention.