"boasted to me" is correct and usable in written English.
You can use it when someone is bragging about something to you. For example: "John boasted to me about his new job that pays twice as much as his old one."
Mr. Hale also boasted to me: "We have really revolutionized the whole racial community.
"There are 18,000 names in my Rolodex," he boasted to me earlier that morning over coffee.
A SUCCESSFUL writer once boasted to me that he could teach any intelligent person how to write fiction on a professional level.
As the captain of a Sydney whalewatch boat boasted to me, there's a 10% increase in new calves being brought back into Australian waters, year on year (although they are certainly not all surviving).
In the summer of 2003, in Fallujah, I met an American soldier who boasted to me of having "lit up" approaching civilian vehicles on the road between Basra and Baghdad, because he wasn't sure who was in them.
Senator Al Franken, who's also laser-focused on jobs, boasted to me that Minnesota is now "The Silicon Valley of windows," because of all the high-tech window manufacturers here.
When the meeting is over one couple, who are both Minutemen, boast to me of their English heritage.
"He used to boast to me about having this power to make people laugh.
I once had an A&R exec boast to me of adding a "Whoa Whoa" to a hook and helping himself to a small piece of the songwriting pie.
As my plane descended towards Scotland, I boasted to the guy next to me that the first thing I'd do in Glasgow was grab a meat pie and a pint of Tennant's 80 shilling ale.
"Even if you demolish me, you will elevate me," he boasted to her at the outset.
