Low-valent Ti-mediated homolytic CÀ O bond cleavage offers unified access to carbon radicals from ubiquitous non-activated tertiary, secondary, and even primary alcohols. In contrast to the representative Ti reagents, which were ineffective for this purpose, "TiCl 2 (cat)"/Zn (cat = catecholate) was found to be specifically active. This method was applied to the addition reactions of radicals to alkenes and exhibited high generality and yields. More than 50 combinations were examined. The excellent cost-efficiency and accessibility of "TiCl 2 (cat)"/Zn further enhance its applicability. Control experiments proved the presence of a carbon radical intermediate and excluded the pathway via alkyl chlorides. Further mechanistic study indicated that the 1 : 2 complex of alkoxide (RÀ O À ) and Ti III is an active species in the CÀ O cleavage.

A reductive radical coupling reaction between non‐activated aliphatic alcohols and styrenes has been discovered through the use of low‐valent Ti‐mediated C−O bond homolysis. A general application of styrene derivatives in radical coupling reactions remains a challenge in organic synthesis. The preliminary investigation revealed that the resulting benzyl radical intermediate behaves differently depending on minor steric differences around the spin center, which results in a lack of generality. The addition of 1,3,5‐trimethyl‐2,5‐cyclohexadiene uniformly hydrogenated the benzyl radicals irrespective of the steric environments of the attacking radicals. Under the optimal reaction conditions, all tertiary, secondary, and primary alcohols were applicable. In this study, alcohols were successfully used directly as radical sources and reacted with a large number of styrenes.

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Low‐valent Ti‐mediated homolytic C−O bond cleavage offers unified access to carbon radicals from ubiquitous non‐activated tertiary, secondary, and even primary alcohols. In contrast to the representative Ti reagents, which were ineffective for this purpose, “TiCl2(cat)”/Zn (cat=catecholate) was found to be specifically active. This method was applied to the addition reactions of radicals to alkenes and exhibited high generality and yields. More than 50 combinations were examined. The excellent cost‐efficiency and accessibility of “TiCl2(cat)”/Zn further enhance its applicability. Control experiments proved the presence of a carbon radical intermediate and excluded the pathway via alkyl chlorides. Further mechanistic study indicated that the 1 : 2 complex of alkoxide (R−O−) and TiIII is an active species in the C−O cleavage.