Refined routes to chlorin building blocks

A compound of Formula XI:

• wherein:
• K1, K2 and K4 are hetero atoms independently selected from the group consisting of N, O, S, Se, Te, and CH;
• K3 is N;
• S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 are independently selected from the group consisting of H, aryl, phenyl, cycloalkyl, alkyl, alkenyl, alkynyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl;
• and wherein from one to four of S1, S2, S3, S4, S5, S6, S7, S8, S9, S10, S11, S12, S13, and S14 may optionally be independently selected linking groups Q, wherein said linking groups Q are of the formula:
• wherein:
• n is from 0 to 10;
• R3 may be present or absent;
• R1, R2, and R3 are each independently selected from the group consisting of ethene, ethyne, aryl, and heteroaryl groups, which aryl and heteroaryl groups may be unsubstituted or substituted one or more times with H, aryl, phenyl, cycloalkyl, alkyl, alkenyl, alkynyl, halogen, alkoxy, alkylthio, perfluoroalkyl, perfluoroaryl, pyridyl, cyano, thiocyanato, nitro, amino, alkylamino, acyl, sulfoxyl, sulfonyl, imido, amido, and carbamoyl;
• Y is a protected or unprotected reactive substituent selected from the group consisting of hydroxy, thio, seleno, telluro, ester, carboxylic acid, boronic acid, phenol, silane, sulfonic acid, phosphonic acid, alkyithiol, formyl, halo, alkenyl, alkynyl, haloalkyl, alkyl phosphonate, alkyl sulfonate, alkyl carboxylate, and alkyl boronate groups;
• and
• Z is selected from the group consisting of halo, alkoxy, and acyloxy.