I believe this Isaac Green to be a son of Joseph Green whose will is on file in the NC Archives in Raleigh NC. The will date 29 Sept 1771 was proved in Jan 1772 and his children are named, Isaac bein one. The county at the time was Tryon & included parts of North & South Carolina. Joseph was identified in Samuel Coburn's Militia Company in 1747 and apparently had a land grant issued in 1753. This will be something you'll want to pursue in your research.
His son Isaac signed for his inheritance: "Received of James McAfee the Sum of one Hundred and Ten Pounds curant money of North Carolina in good Trade agreable to the former prasement and Do Hereby acknowledg my Self my heirs and as Signs forever fully Satisfied there With for my part of an estate Left and bequeathed to me by my father Joseph Green Dessed and I do hereby forever quite and Clame to any of sc. astate Ither Real or parsonal Received this Second Day of July 1784."
The receipt was witnessed and signed by Jacob Collins and Mary Collins with her mark.
Now as to the Isaac Green in Greenville SC, I found this info in my files:
18 February 1792, Isaac sold 100 acres of his property in Greenville County, SC, to Elisha Smith. For 10# sterling, Mr Smith received acreage on both sides of Kemps Brook, the border crossed the Caen swamp and mouth of a small branch between where Smith and Elisha Simmons lived. It included the plantation where Mr Smith lived, and was the SE corner of the 692 acres granted 7 November 1791 by Gov Charles Pinckney to Isaac. Isaac signed the transaction, which was witnessed by John Blackwall, Hugh Parks, and John Anderson. Mr Blackwell signed an oath before Robert McAfee. The deed was recorded 1 July 1798, in book E, page 56.
After Isaac himself died:
Letters of administration granted to Abraham Green on the estate of Isaac Green, dec'd, on 8 Feb. 1831.
4 March 1831, Greenville Co. South Carolina Estates #178: Captain Isaac Green
Inventory of goods and chattels of Isaac Green, deceased, made by Abraham Green, administrator. Buyers at the estate sale included Phebe Green, Isaac Green Jr., Abraham Green, Jacob Green, Leroy H. Green, Clabron Waddill, and Joseph Bates.
Final settlement of estate of Isaac Green made 14 May 1832 by administrator Abraham Green.
---after taking into consideration previous advances made to said heirs, total distribution was made to the widow and eight children; after deducting the widow's 1/3 the remaining $4464.88 was divided in equal lots of $558.11 to each of the eight children (or representatives) as follows:
Joseph Green, L. H. Green, William Green, Joseph Bates, Abraham Green, C. Waddill, Isaac Green, Jacob Green.
Later his family made the following transactions abstracted from the Greenville County, SC, deeds:
S:1--Phoebe Green to son Jacob Green, both of Greenville District; bill of sale 23 Sept. 1835;--negro boy Pleasant, aged 4 years.
U:194--Joseph Green and Frances Benson; --marriage contract dated 3 Jan 1843.
U:243--Jacob Green on deed dated 11 Sept 1843.
U:263--Phoebe Green to James McCarter; Mortgage 16 Oct 1843; Mortgage on three negroes, man Willis, woman Mary, and her youngest child Betsy, for $500. Joseph Green Wittness.
U:579--Leroy H. Green to Robert Wynne; Deed 9 Dec 1844 his wife Fanny released.
Hope this helps in some way.