An important feature of our reaction is the
versatility of the introduced boronic ester
group, which can be readily functionalized.
For a demonstration, we chose protected phenol
2obecause of the importance of phenol deri-
vatives in organic chemistry ( 32 )andthedif-
ficulty in directmetafunctionalization of phenol.
Compound2o, which was readily synthesized
in high yield and with highmetaselectivity by
borylation of protected phenol1ounder ourconditions (Fig. 3), could be transformed to a
variety ofmeta-substituted phenols such as
resorcinol ( 5 ),meta-iodophenol ( 6 ),meta-
(1-piperidinyl)phenol ( 7 , as the silyl ether),
3-deuteriophenol ( 8 , as the silyl ether), andSCIENCEscience.org 11 FEBRUARY 2022¥VOL 375 ISSUE 6581 661
Fig. 3. Reaction scope.Reactions were conducted with substrate 1
(0.20 mmol), HBpin (0.40 mmol), [IrOMe(cod)] 2 (2 mol%), andL12(4 mol%)
in dioxane at 90°C for 16 hours. The yield was determined by isolation (see
supplementary materials); the total reaction yield, estimated using gas
chromatography or^1 H NMR spectroscopy in the presence of an internal
standard, is shown in parentheses. The selectivity, expressed as ( 2 + 3 )/ 4 , was
determined using gas chromatography or^1 H NMR. *Isolated as singlemeta
isomer 2 by gel permeation chromatography.†Isolated as a mixture of 2 and 4.
‡The reaction was conducted on a 0.1-mmol scale. §B 2 pin 2 (110 mol%) was used
instead of HBpin. Et, ethyl; Boc,tert-butoxycarbonyl.RESEARCH | REPORTS