Buchwald-Hartwig coupling troubleshooting

I am conducting a synthesis using below scheme.


[![reaction scheme](https://i.stack.imgur.com/XZPCc.png)](https://i.stack.imgur.com/XZPCc.png)


And Below is some information about my reaction history.


* The basic condition is 1 eq of 1-aza-18-crown-6, 1.4 eq of 3-bromothiophene, 1 mol% of DavePhos Pd G4, 1 mol% of DavePhos, 2 eq of NaOtBu, toluene as solvent, and conducted at 100 ℃ for 24 h.
* I chose the P ligand as DavePhos referring to [this paper](https://pubs.acs.org/doi/abs/10.1021/jo005577d).
* After 24 h, the reaction mixture is cooled to room temperature, taken up into 100 mL of dichloromethane, filtered through Celite, concentrated using rotovap, and dried in vacuum.
* As I checked the GC/MS spectrum of the sample, the peak of 1-aza-18-crown-6 (SM2) is relatively much larger than that of 3-bromothiophene (SM1), and the product peak is also very small. That is, conversion is too low.
* Below is the GC/MS spectrum. The unassigned peaks are unknown compounds or maybe impurities in GC column. The mass spectrum of each peak was omitted.


[![GC-MS spectrum1](https://i.stack.imgur.com/2ew7p.png)](https://i.stack.imgur.com/2ew7p.png)


* As I decreased the amount of catalyst and temperature, no product peak was observed.
* As I increased the amount of catalyst to 3 mol% and temperature to 120 ℃, the peak of SM1 was largely decreased, but also the peak of product was.
* Below is the GC/MS spectrum in the case of 3 mol% of catalyst loading. The unassigned peaks are unknown compounds or maybe impurities in GC column. The mass spectrum of each peak was omitted.


[![GC-MS spectrum2-1](https://i.stack.imgur.com/mdy7g.png)](https://i.stack.imgur.com/mdy7g.png)
[![GC-MS spectrum2-2](https://i.stack.imgur.com/PrW1K.png)](https://i.stack.imgur.com/PrW1K.png)
[![GC-MS spectrum2-3](https://i.stack.imgur.com/aCcer.png)](https://i.stack.imgur.com/aCcer.png)


My doubtful point is that there are no remarkable byproduct peaks although the peak of SM1 is very small in contrast to the fact that the peak of SM2 is very large. In the case of 3 mol% catalyst loading the peak of bithiophene, which is the representative byproduct of Buchwald-Hartwig reaction, was observed, but it is also very small. If there were any large byprodut peaks, I would try to find a solution, however this situation is uninterpretable. What was going on in my reaction mixture?


