Handbook of Functionalized Organometallics Applications in S

MeO
O
64
O
3 Functionalized Organoborane Derivatives in Organic Synthesis
base in 64% yield [50]. It should be noted that the product 72 was obtained previously
only in a yield of 19% under standard Suzuki-coupling conditions
(Scheme 3.32) [51].
The macrocyclic core of diazonamide A, a cytotoxic marine natural product has
been prepared by Vedejs via Suzuki coupling of boronic acid 73 and the triflate 74
yielding interconverting mixture of two atropisomers that on treatment with LDA
at ±23 C affords the macrocyclic ketone 75 in 57% yield (Scheme 3.33) [52].
B(OH) 2
O
Me
TfO
O
N
N
Boc
1) PdCl 2(dppf), THF,
Cs 2CO 3, 65 ºC, 65 %
2) LDA, THF, -23 ºC
73 74 O
TESO
Me
O
Scheme 3.33 Macrocyclic heterocycle synthesis.
O
N
O
O
75: 57%
N Boc
The synthesis of anti-MRSA carbapenam has been reported as a multigram
scale synthesis involving Suzuki±Miyaura cross-coupling between carbapenam triflate
76 and the highly functionalized aryl boronate salt 77 as the key step by
Merck scientists yielding polyfunctional product 78 in 60% yield over four steps.
It highlights the versatility and efficiency of the Suzuki±Miyaura cross-coupling
reaction (Scheme 3.34) [53].
HO
H H
N
Me O
Me
OTf
CO 2pNB
(HO) 2B
76 77
Me
H H
N
CO 2pNB
O
78: 60%
O
N
2TfO -
N
O
nTfO - ;2-nBr -
N
O
NH 2
N
NH 2
1) Pd(dba) 2, LiCO3 DMF/CH2Cl2/H2O 30 - 35 ºC
2) pH 2.2 - 2.4
THF/H2O 3) NaOTf
Scheme 3.34 Synthesis of a carbapenam derivative via Suzuki±Miyaura cross-coupling.
Kozikowski has reported the synthesis of a novel class of spirocyclic cocaine
analogs 79a and b by using Suzuki cross-coupling of the ortho-functionalized aryl