TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Components: The reducing agent is sodium borohydride.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Process: In process (p1), the reducing step is carried out with sodium borohydride (NaBH4) in an organic solvent. In process (p2), the base is present and added as a preformed base; the base is formed in situ, and its conjugate acid has a pKa less than that of the conjugate acid of the Grignard reagent (preferably hindered). The process (p2) further involves decomplexing 1,9-diacyldipyrromethane from the metal complex by combining complex with hydroxide, alcohol and/or water to form a product; combining the product with a compound of formula R1R2M'X'2 in the presence of a base to form a metal complex of formula DM'R1R2 in mixed reaction product, and then separating the metal complex from the mixed reaction product; and reducing the metal complex with a reducing agent to form a diol from 1,9-diacyldipyrromethane, and then condensing the diol with a dipyrromethane to form a porphyrin ring compound. In process (p3), the substituting step is a halogenating step. The process (p3) further involves forming a carbinol reduction product of 1-acyl-9-substituted dipyrromethane boron complex; then condensing the carbinol reduction product with a chlorin western half in an organic solvent in the presence of an acid to form a condensation product; and then oxidatively cyclizing the condensation product in an organic solvent in the presence of a base, an oxidant and a metal salt to produce a chlorin.M' = tin, silicon, germanium or lead;X' = halo, acetoxy, acac or OTf; andDH2 = 1,9-diacyldipyrromethane.Preferred Components: The base is the deprotonated form of a compound selected from tetraalkylpiperidine, dicycloalkylamine, and disilzane. SPECIFIC COMPOUNDS - 5,10-bis(4-methylphenyl)-15,20-diphenylporphyrin is a preferred example of the porphyrin compound.    EXAMPLE - A sample of 1-tolylcarbonyldipyrromethane-boron complex-dibutylboron (0.116 gm) was dissolved in dry tetrahydrofuran (THF)/methanol (3:1, 6 ml) at room temperature under argon. Sodium borohydride (0.238 gm) was added in small portions with rapid stirring. After the reaction was complete (about 40 minutes), the reaction mixture was worked up with ammonium chloride and dichloromethane (CH2Cl2). The organic phase was separated, washed with water, dried, and concentrated under reduced pressure to yield the monocarbinol as a foam-like solid. To the flask containing the dipyrromethane-moncarbinol (0.250 mmol assuming quantitative reduction) was added reagent-grade CH2Cl2 (50 ml). The mixture was stirred for 5 minutes to achieve dissolution, and then ytterbium triflate (Yb(OTf)3) (0.010 gm) was added. The reaction was monitored by absorption spectroscopy (by injecting a 50 mul reaction aliquot into a solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) (300 mul, 0.01 M in toluene); then 50 mul of the resulting oxidized mixture was dissolved in CH2Cl2/ethanol (3:1, 3 ml), and the absorption spectrum was recorded). After acid-catalyzed condensation for 60 minutes, DDQ (0.085 mg) was added. The mixture was stirred at room temperature for 1 hour. Triethylamine was added and the entire reaction mixture was passed through a pad of silica and eluted with CH2Cl2 until the eluant was no longer purple. The resulting porphyrin-containing solution was concentrated by rotary evaporation to give a purple solid. The solid was triturated with methanol and dried in vacuo affording 5,10-bis(4-methylphenyl)-15,20-diphenylporphyrin as a crystalline purple solid (yield = 0.021 g, 26%).