Table 1. Boron mediated disproportionation of formate anions into methoxyboranes ^a .

Entry	R2B	BaseH+	t c ]	T [°C]	Solvent	Yield b [%]
1	BBN	Et3NH+	>48 h	130	d 8-THF	<5
2	BBN	Et3NH+	>48 h	130	C6D6	<5
3	BBN	Et3NH+	4	150	CD3CN	33
4	BBN	Et3NH+	10.5	130	CD3CN	39
5	BBN	iPr2EtNH+	4.5	130	CD3CN	50
6	BCy2	Et3NH+	2.5	130	CD3CN	<5
7	BCy2	Et3NH+	7	120	CD3CN	38

^aReaction conditions: 0.125 mmol 1^– or 2^–, 0.4 mL solvent.

^bYields determined by ¹H NMR using mesitylene (10 μL); mean value over at least 2 runs.

^cTime required to obtain >95% conversion of formate.