## 2 Results and Discussion
### Comparison to Thermal Conditions  
With optimized conditions in hand, the direct comparison of thermal conditions to the microwave was assessed. Using a series of commercially available alkynes, an array of diynes was prepared and their yields were compared to that obtained by thermal reaction at 60 \({}^{\circ}\)C for 16 h. Reactions were performed with alkynes harboring a range of chemical functionality including aromatic rings (**1**, **3**, and **4**), aliphatic chains (**2**), ethers (**3**), basic residues (**4**, **5**), and alcohols (**6**) with the propargyl alcohol derivatized resin to yield a series of diynes (**7-12**). Interestingly, the previous conditions were not found to be optimal for all soluble alkynes, perhaps due to their differential absorbance of microwave irradiation. Thus, increasing reaction times to 20 min seemed to afford maximal results and enhanced yields (Table 2). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Temperature (\({}^{\circ}\)C)** & **Time (min)** & **Yield (\%)** \\ \hline
40 & 20 & 0 \\
60 & 5 & 26 \\
60 & 10 & 74 \\
80 & 5 & 12 \\
80 & 10 & 77 \\
80 & 20 & 77 \\
100 & 5 & 0 \\
100 & 10 & 63 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Microwave Optimization of the Glaser-Hay Reaction. The assembly of the diyne library demonstrated several important factors must be considered when using the microwave in this technology. Overall, microwave yields were good to excellent (67%-92%), but were highly dependent on the soluble alkyne. In the case of incomplete reaction, starting materials were removed via filtration through a silica plug. Alkynes with basic, coordinating moieties (**4-5**) were obtained in higher yields in the microwave relative to the thermal conditions. We hypothesize this is due to the rate enhancement in the microwave affording catalysis prior to catalyst poisoning by soluble alkyne coordination to the copper catalyst. Additionally, somewhat nonpolar alkynes (**1-3**) appear to be less reactive under microwave irradiation, resulting in lower yields than thermal conditions. Attempts to extend reaction times in these cases did not result in any increase of diyne product. Due to the differences in soluble alkynes, we also investigated the influence of the immobilized alkyne via derivitization of the trityl chloride resin with 4-ethylynyl benzyl alcohol. This resin was then reacted with the same set of soluble alkynes employed with the propargyl alcohol resin. Using the previously described microwave conditions resulted in substantial amounts of unreacted alkyne on the resin, requiring further optimization of conditions. Ultimately, this resin was found to be highly \begin{table}
\begin{tabular}{c c c c}  & & 1) CuI/TMEDA & & \\  & & & Thermal\({}^{\text{a}}\) or MW\({}^{\text{b}}\) & HO \\  & & & 2) 2\% TFA, DCM, \(\text{rf}\), 1 h & \\  & & & \\ \end{tabular}
\end{table} 
Table 2: Propargyl Alcohol Derivatized Resin Glaser-Hay Reactions. adsorbing of microwave irradiation, heating much more rapidly than the propargyl alcohol resin. This resulted in very low microwave input into the reactions. To rectify this, the reaction was subjected to 2 min pulses at 120 \({}^{\circ}\)C for a total of 20 min (Table 3). Each pulse heats the reaction to 120 \({}^{\circ}\)C for a 2-min interval, followed by cooling to room temperature prior to resubmission to microwave irradiation. \begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{1}{c}{**Alkyne**} & \multicolumn{1}{c}{**Product**} & \multicolumn{1}{c}{**\% Yield**} & \multicolumn{1}{c}{**\% Yield**} \\ \hline \multicolumn{1}{c}{**Alkyne**} & \multicolumn{1}{c}{**Product**} & \multicolumn{1}{c}{**Thermal** 1 **} & \multicolumn{1}{c}{**Microwave** 2 **} \\ \hline \multicolumn{1}{c}{**PH**} & \multicolumn{1}{c}{**PH**} & \multicolumn{1}{The series of diynes (**13-18**) were obtained in good to excellent yield, ranging from 76%-86%.