We are currently negotiating the sale

The notary must certify, with his signature, that there has been a legal transfer of currency, between the buyer and the seller, not to perceive - in the name of the state, the taxes on the purchase, that is 10% of the cadastral value of the motionless. If the buyer transfers the sums from a foreign account to another foreign account, the notary is not able to certify that the transfer has been made, so the sale would be nothing - and even come up against the rule called anti-money laundering - finally, I it appears that in the USA there is a regulation on the export of capital, or on the purchase of goods abroad, according to which those who buy abroad must prove the origin of the money, the transfer of the same. If the transfer does not take place, the tax office, as it does for foreign properties, of a US citizen.More information on the work of notaries in Italy, at the following addresshttps://www.notariato.it/en Ugo - by Lifeinitaly.it

the notary - being an Italian public official - would have no authority to check and certify - in 30/60 minutes, the signing of a purchase deed - a currency transfer between the two parties - if the person making it (two US banks) is outside the banking control of shenghen area - Not subjected to the banking laws to which Italy adheres - Basel I - II - III - European anti-money laundering laws, which are different from those of other countries -Please understand, that in the fiscal sector, from all the countries of the world - there is a certification standard, from the primary to the final - The last link in the chain, in a deed of sale, is the notary. Its certification must - FORCE - be based on the primary certifications, of the rules accepted by the central banks -I give a practical example, You sell me a house, I pay you with a check drawn on an American bank - You would give me the receipt, without any entity in the country where your house is located, can guarantee for the goodness of the check ?Here, the notary would find himself in the same situation - guaranteeing, with his signature, under his personal legal and financial responsibility - that you received the value of the piece of paper (check) and therefore the house is no longer yours 

You can buy in USD, but the notary will need proof of the trasnfer and the euro exchange rate decided upon.  The TRN/CRO will be necessary - and this means that the buyer needs to send the money to your account before the sale, even a few minutes before , and the notary can write in the issuing bank, the receiving bank and the transfer reference into the act of sale so it is all traceable bythe Italian authorities.   Obviosuly, as you said, thebuyer will pay the notary and taxes in euros to the notary.    Screen shots of the transfer are useful to show it has gone, (and ideally received).   However, each notary works differently and you should check with the notary you are planning to use that this would be ok with him. 

casa del campanileAre you really sure that your buyer is willing to transfer his dollars, in your current, before you sign the deed of sale?The operation that you want to put in place, in commercial language, is called, TRIANGULATION. Triangulation is regulated by international trade agreements, signed by many countries in the world. USA and Italy, they have a commercial agreement in place. In order to make a triangulation, all the parties involved must be registered in the chamber of commerce of their country, and fiscally registered as regular exporters. To settle cash transfers of a triangulation, you need current accounts in foreign currency, normally US dollars (you have an advantage!)The seller sends the buyer an invoice with the amount to be paid, the buyer issues a Confirmed and Guaranted Letter of Credit (letter of credit, confirmed by his bank = the funds are frozen in the buyer's account) and guaranteed by the seller's bank (which received from the bank of the buyer, a funds freeze on the buyer's account).The goods are loaded on the means of transport. Upon arrival the buyer or his representative, goes to the customs offices, receives a copy of the transport documents, from which it appears that the goods are in the destination country, with these documents he goes to his bank and asks that the CGLC , be released against the seller - the buyer, with the release receipt, returns to Customs, pays all the excise duties, duties, absolves the bureaucracy, from this moment the goods are his.Doing all this for a home in Italy, I'm afraid it's not possible.If you really want to negotiate the sale in Dollars, you can open your non-resident account, in dollars, on the Bank of America in Italy, and ask the bank to issue, with provision on theAmerican account of the seller, a bank draft in your name, to be shown to the notary on the day of the deed. After signing the mortgage deed, in which the notary has registered the check data, you will go to the BOA and pay the check in your dollar account.I have, however, my doubts that the BOA can issue a check in Italy, to be worth in an account in the USA, and ESPECIALLY, that it is willing to make available, on your account in the US, the exact sum in dollars, without get you transfer fees and Italian taxes on the exported capital. 

We did this in GBP via UK banks, okay payment was mae in advance of the sale, but there was no problem doing so...