The Raptors also sent center Zan Tabak and forward Popeye Jones to the Celtics for guards Chauncey Billups and Dee Brown and forwards John Thomas and Roy Rogers.
Anderson, acquired in a trade last week for star guard Damon Stoudamire, had refused to report to Toronto, a franchise troubled by front-office instability and an 11-40 record.
Billups, the key for Toronto, was averaging 11.1 points a game for the Celtics. The rookie was the Celtics first choice, third overall, in last summer's draft.
Brown, a seven-year veteran, was averaging 6.8 points for Boston. Rogers and Thomas were little-used reserves.
Anderson, a former all-star, has struggled this season, averaging 12.6 points and 5.4 assists for Portland. Jones and Tabak are on the disabled list.
The Phoenix Suns traded Cedric Ceballos to the Dallas Mavericks for Dennis Scott in a swap of scoring forwards with questionable behavior who are free agents at the end of the season. The 28-year-old Ceballos leaves the Suns for the second time in his career. He is averaging 9.5 points and 4.3 rebounds in 35 games. Scott scored 17 points against the Suns on Tuesday, lifting his average to 13.6 points in 52 games.
The Vancouver Grizzlies sent Otis Thorpe back where his NBA career began, trading the veteran forward along with guard Chris Robinson to the Sacramento Kings for forward Michael Smith and guard Bobby Hurley.
Thorpe, 35, was the ninth overall selection of the old Kansas City Kings in the 1984 draft.
Peeler was averaging 9.9 points, West 4.1.